Thèses : « CHIM/07 »

1

Soccio, Michelina <1980&gt. « Sintesi, caratterizzazione e correlazioni proprietà-struttura di poliesteri innovativi per usi speciali ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/713/1/Tesi_Soccio_Michelina.pdf.

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2

Soccio, Michelina <1980&gt. « Sintesi, caratterizzazione e correlazioni proprietà-struttura di poliesteri innovativi per usi speciali ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/713/.

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3

Gigli, Matteo <1984&gt. « Novel etheroatom containing aliphatic polyesters for biomedical and environmental applications ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5617/1/Gigli_Matteo_tesi.pdf.

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Biodegradable polymers for short time applications have attracted much interest all over the world. The reason behind this growing interest is the incompatibility of the polymeric wastes with the environment where they are disposed after usage. Synthetic aliphatic polyesters represent one of the most economically competitive biodegradable polymers. In addition, they gained considerable attention as they combine biodegradability and biocompatibility with interesting physical and chemical properties. In this framework, the present research work focused on the modification by reactive blending and polycondensation of two different aliphatic polyesters, namely poly(butylene succinate) (PBS) and poly(butylene 1,4-cyclohexanedicarboxylate) (PBCE). Both are characterized by good thermal properties, but their mechanical characteristics do not fit the requirements for applications in which high flexibility is requested and, moreover, both show slow biodegradation rate. With the aim of developing new materials with improved characteristics with respect to the parent homopolymers, novel etheroatom containing PBS and PBCE-based fully aliphatic polyesters and copolyesters have been therefore synthesized and carefully characterized. The introduction of oxygen or sulphur atoms along the polymer chains, by acting on chemical composition or molecular architecture, tailored solid-state properties and biodegradation rate: type and amount of comonomeric units and sequence distribution deeply affected the material final properties owing, among all, to the hydrophobic/hydrophilic ratio and to the different ability of the polymer to crystallize. The versatility of the synthesized copolymers has been well proved: as a matter of fact these polymers can be exploited both for biomedical and ecological applications. Feasibility of 3D electrospun scaffolds has been investigated, biocompatibility studies and controlled release of a model molecule showed good responses. As regards ecological applications, barrier properties and eco-toxicological assessments have been conducted with outstanding results. Finally, the ability of the novel polyesters to undergo both hydrolytic and enzymatic degradation has been demonstrated under physiological and environmental conditions.

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4

Gigli, Matteo <1984&gt. « Novel etheroatom containing aliphatic polyesters for biomedical and environmental applications ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5617/.

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Biodegradable polymers for short time applications have attracted much interest all over the world. The reason behind this growing interest is the incompatibility of the polymeric wastes with the environment where they are disposed after usage. Synthetic aliphatic polyesters represent one of the most economically competitive biodegradable polymers. In addition, they gained considerable attention as they combine biodegradability and biocompatibility with interesting physical and chemical properties. In this framework, the present research work focused on the modification by reactive blending and polycondensation of two different aliphatic polyesters, namely poly(butylene succinate) (PBS) and poly(butylene 1,4-cyclohexanedicarboxylate) (PBCE). Both are characterized by good thermal properties, but their mechanical characteristics do not fit the requirements for applications in which high flexibility is requested and, moreover, both show slow biodegradation rate. With the aim of developing new materials with improved characteristics with respect to the parent homopolymers, novel etheroatom containing PBS and PBCE-based fully aliphatic polyesters and copolyesters have been therefore synthesized and carefully characterized. The introduction of oxygen or sulphur atoms along the polymer chains, by acting on chemical composition or molecular architecture, tailored solid-state properties and biodegradation rate: type and amount of comonomeric units and sequence distribution deeply affected the material final properties owing, among all, to the hydrophobic/hydrophilic ratio and to the different ability of the polymer to crystallize. The versatility of the synthesized copolymers has been well proved: as a matter of fact these polymers can be exploited both for biomedical and ecological applications. Feasibility of 3D electrospun scaffolds has been investigated, biocompatibility studies and controlled release of a model molecule showed good responses. As regards ecological applications, barrier properties and eco-toxicological assessments have been conducted with outstanding results. Finally, the ability of the novel polyesters to undergo both hydrolytic and enzymatic degradation has been demonstrated under physiological and environmental conditions.

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5

Leonardi, Francesca <1986&gt. « Self-Assembled Monolayers (SAMs) in Organic Field-Effect Transistors ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6461/1/Leonardi__dottorato.pdf.

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Organic printed electronics is attracting an ever-growing interest in the last decades because of its impressive breakthroughs concerning the chemical design of π-conjugated materials and their processing. This has an impact on novel applications, such as flexible-large-area displays, low- cost printable circuits, plastic solar cells and lab-on-a-chip devices. The organic field-effect transistor (OFET) relies on a thin film of organic semiconductor that bridges source and drain electrodes. Since its first discovery in the 80s, intensive research activities were deployed in order to control the chemico-physical properties of these electronic devices and consequently their charge. Self-assembled monolayers (SAMs) are a versatile tool for tuning the properties of metallic, semi-conducting, and insulating surfaces. Within this context, OFETs represent reliable instruments for measuring the electrical properties of the SAMs in a Metal/SAM/OS junction. Our experimental approach, named Charge Injection Organic-Gauge (CIOG), uses OTFT in a charge-injection controlled regime. The CIOG sensitivity has been extensively demonstrated on different homologous self-assembling molecules that differ in either chain length or in anchor/terminal group. One of the latest applications of organic electronics is the so-called “bio-electronics” that makes use of electronic devices to encompass interests of the medical science, such as biosensors, biotransducers etc… As a result, thee second part of this thesis deals with the realization of an electronic transducer based on an Organic Field-Effect Transistor operating in aqueous media. Here, the conventional bottom gate/bottom contact configuration is replaced by top gate architecture with the electrolyte that ensures electrical contact between the top gold electrode and the semiconductor layer. This configuration is named Electrolyte-Gated Field-Effect Transistor (EGOFET). The functionalization of the top electrode is the sensing core of the device allowing the detection of dopamine as well as of protein biomarkers with ultra-low sensitivity.

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6

Leonardi, Francesca <1986&gt. « Self-Assembled Monolayers (SAMs) in Organic Field-Effect Transistors ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6461/.

Texte intégral

Résumé :

Organic printed electronics is attracting an ever-growing interest in the last decades because of its impressive breakthroughs concerning the chemical design of π-conjugated materials and their processing. This has an impact on novel applications, such as flexible-large-area displays, low- cost printable circuits, plastic solar cells and lab-on-a-chip devices. The organic field-effect transistor (OFET) relies on a thin film of organic semiconductor that bridges source and drain electrodes. Since its first discovery in the 80s, intensive research activities were deployed in order to control the chemico-physical properties of these electronic devices and consequently their charge. Self-assembled monolayers (SAMs) are a versatile tool for tuning the properties of metallic, semi-conducting, and insulating surfaces. Within this context, OFETs represent reliable instruments for measuring the electrical properties of the SAMs in a Metal/SAM/OS junction. Our experimental approach, named Charge Injection Organic-Gauge (CIOG), uses OTFT in a charge-injection controlled regime. The CIOG sensitivity has been extensively demonstrated on different homologous self-assembling molecules that differ in either chain length or in anchor/terminal group. One of the latest applications of organic electronics is the so-called “bio-electronics” that makes use of electronic devices to encompass interests of the medical science, such as biosensors, biotransducers etc… As a result, thee second part of this thesis deals with the realization of an electronic transducer based on an Organic Field-Effect Transistor operating in aqueous media. Here, the conventional bottom gate/bottom contact configuration is replaced by top gate architecture with the electrolyte that ensures electrical contact between the top gold electrode and the semiconductor layer. This configuration is named Electrolyte-Gated Field-Effect Transistor (EGOFET). The functionalization of the top electrode is the sensing core of the device allowing the detection of dopamine as well as of protein biomarkers with ultra-low sensitivity.

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7

Barbalinardo, Marianna <1981&gt. « Design and fabrication of biocompatible scaffolds for the regeneration of tissues ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6462/1/Tesi_dottorato_MBarbalinardo.pdf.

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Regenerative medicine and tissue engineering attempt to repair or improve the biological functions of tissues that have been damaged or have ceased to perform their role through three main components: a biocompatible scaffold, cellular component and bioactive molecules. Nanotechnology provide a toolbox of innovative scaffold fabrication procedures in regenerative medicine. In fact, nanotechnology, using manufacturing techniques such as conventional and unconventional lithography, allows fabricating supports with different geometries and sizes as well as displaying physical chemical properties tunable over different length scales. Soft lithography techniques allow to functionalize the support by specific molecules that promote adhesion and control the growth of cells. Understanding cell response to scaffold, and viceversa, is a key issue; here we show our investigation of the essential features required for improving the cell-surface interaction over different scale lengths. The main goal of this thesis has been to devise a nanotechnology-based strategy for the fabrication of scaffolds for tissue regeneration. We made four types of scaffolds, which are able to accurately control cell adhesion and proliferation. For each scaffold, we chose properly designed materials, fabrication and characterization techniques.

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8

Barbalinardo, Marianna <1981&gt. « Design and fabrication of biocompatible scaffolds for the regeneration of tissues ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6462/.

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Regenerative medicine and tissue engineering attempt to repair or improve the biological functions of tissues that have been damaged or have ceased to perform their role through three main components: a biocompatible scaffold, cellular component and bioactive molecules. Nanotechnology provide a toolbox of innovative scaffold fabrication procedures in regenerative medicine. In fact, nanotechnology, using manufacturing techniques such as conventional and unconventional lithography, allows fabricating supports with different geometries and sizes as well as displaying physical chemical properties tunable over different length scales. Soft lithography techniques allow to functionalize the support by specific molecules that promote adhesion and control the growth of cells. Understanding cell response to scaffold, and viceversa, is a key issue; here we show our investigation of the essential features required for improving the cell-surface interaction over different scale lengths. The main goal of this thesis has been to devise a nanotechnology-based strategy for the fabrication of scaffolds for tissue regeneration. We made four types of scaffolds, which are able to accurately control cell adhesion and proliferation. For each scaffold, we chose properly designed materials, fabrication and characterization techniques.

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9

Hemmatian, Zahra <1980&gt. « Nano-fabrication of complex functional structures using non- conventional lithography ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6476/1/Tesi_dottorato_ZHemmattian.pdf.

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In Chapter 1 I will present a brief introduction on the state of art of nanotechnologies, nanofabrication techniques and unconventional lithography as a technique to fabricate the novel electronic device as resistive switch so-called memristor is shown. In Chapter 2 a detailed description of the main fabrication and characterization techniques employed in this work is reported. Chapter 3 parallel local oxidation lithography (pLOx) describes as a main technique to obtain accurate patterning process. All the effective parameters has been studied and the optimized condition observed to highly reproducible with excellent patterned nanostructures. The effect of negative bias, calls local reduction (LR) studied. Moreover, the use of AC bias shows faster patterning process respect to DC bias. In Chapter 4 (metal/ e-SiO2/ Si nanojunction) it is shown how the electrochemical oxide nanostructures by using pLOx can be used in the fabrication of novel devices call memristor. We demonstrate a new concept, based on conventional materials, where the lifetime problem is resolved by introducing a “regeneration” step, which restores the nano-memristor to its pristine condition by applying an appropriate voltage cycle. In Chapter 5 (Graphene/ e-SiO2/ Si), Graphene as a building block material is used as an electrode to selectively oxidize the silicon substrate by pLOx set up for the fabrication of novel resistive switch device. In Chapter 6 (surface architecture) I will show another application of pLOx in biotechnology is shown. So the surface functionalization combine with nano-patterning by pLOx used to design a new surface to accurately bind biomolecules with the possibility of studying those properties and more application in nano-bio device fabrication. So, in order to obtain biochips, electronic and optical/photonics devices Nano patterning of DNA used as scaffolds to fabricate small functional nano-components.

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10

Hemmatian, Zahra <1980&gt. « Nano-fabrication of complex functional structures using non- conventional lithography ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6476/.

Texte intégral

Résumé :

In Chapter 1 I will present a brief introduction on the state of art of nanotechnologies, nanofabrication techniques and unconventional lithography as a technique to fabricate the novel electronic device as resistive switch so-called memristor is shown. In Chapter 2 a detailed description of the main fabrication and characterization techniques employed in this work is reported. Chapter 3 parallel local oxidation lithography (pLOx) describes as a main technique to obtain accurate patterning process. All the effective parameters has been studied and the optimized condition observed to highly reproducible with excellent patterned nanostructures. The effect of negative bias, calls local reduction (LR) studied. Moreover, the use of AC bias shows faster patterning process respect to DC bias. In Chapter 4 (metal/ e-SiO2/ Si nanojunction) it is shown how the electrochemical oxide nanostructures by using pLOx can be used in the fabrication of novel devices call memristor. We demonstrate a new concept, based on conventional materials, where the lifetime problem is resolved by introducing a “regeneration” step, which restores the nano-memristor to its pristine condition by applying an appropriate voltage cycle. In Chapter 5 (Graphene/ e-SiO2/ Si), Graphene as a building block material is used as an electrode to selectively oxidize the silicon substrate by pLOx set up for the fabrication of novel resistive switch device. In Chapter 6 (surface architecture) I will show another application of pLOx in biotechnology is shown. So the surface functionalization combine with nano-patterning by pLOx used to design a new surface to accurately bind biomolecules with the possibility of studying those properties and more application in nano-bio device fabrication. So, in order to obtain biochips, electronic and optical/photonics devices Nano patterning of DNA used as scaffolds to fabricate small functional nano-components.

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11

Tortorella, Silvia <1985&gt. « Patterning soft matter for cell culturing ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7039/1/Silvia_Tortorella_TESI.pdf.

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In the search to understand the interaction between cells and their underlying substrates, life sciences are beginning to incorporate micro and nano-technology based tools to probe, measure and improve cellular behavior. In this frame, patterned surfaces provide a platform for highly defined cellular interactions and, in perspective, they offer unique advantages for artificial implants. For these reasons, functionalized materials have recently become a central topic in tissue engineering. Nanotechnology, with its rich toolbox of techniques, can be the leading actor in the materials patterning field. Laser assisted methods, conventional and un-conventional lithography and other patterning techniques, allow the fabrication of functional supports with tunable properties, either physically, or topographically and chemically. Among them, soft lithography provides an effective (and low cost) strategy for manufacturing micro and nanostructures. The main focus of this work is the use of different fabrication approaches aiming at a precise control of cell behavior, adhesion, proliferation and differentiation, through chemically and spatially designed surfaces.

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12

Tortorella, Silvia <1985&gt. « Patterning soft matter for cell culturing ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7039/.

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In the search to understand the interaction between cells and their underlying substrates, life sciences are beginning to incorporate micro and nano-technology based tools to probe, measure and improve cellular behavior. In this frame, patterned surfaces provide a platform for highly defined cellular interactions and, in perspective, they offer unique advantages for artificial implants. For these reasons, functionalized materials have recently become a central topic in tissue engineering. Nanotechnology, with its rich toolbox of techniques, can be the leading actor in the materials patterning field. Laser assisted methods, conventional and un-conventional lithography and other patterning techniques, allow the fabrication of functional supports with tunable properties, either physically, or topographically and chemically. Among them, soft lithography provides an effective (and low cost) strategy for manufacturing micro and nanostructures. The main focus of this work is the use of different fabrication approaches aiming at a precise control of cell behavior, adhesion, proliferation and differentiation, through chemically and spatially designed surfaces.

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13

Kyndiah, Adrica <1987&gt. « Interfacial interactions, charge transport and growth phenomena in Organic Field Effect Transistors ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7100/1/Adrica_Kyndiah_Tesi.pdf.

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Organic electronics is an emerging field with a vast number of applications having high potential for commercial success. Although an enormous progress has been made in this research area, many organic electronic applications such as organic opto-electronic devices, organic field effect transistors and organic bioelectronic devices still require further optimization to fulfill the requirements for successful commercialization. The main bottle neck that hinders large scale production of these devices is their performances and stability. The performance of the organic devices largely depends on the charge transport processes occurring at the interfaces of various material that it is composed of. As a result, the key ingredient needed for a successful improvement in the performance and stability of organic electronic devices is an in-depth knowledge of the interfacial interactions and the charge transport phenomena taking place at different interfaces. The aim of this thesis is to address the role of the various interfaces between different material in determining the charge transport properties of organic devices. In this framework, I chose an Organic Field Effect Transistor (OFET) as a model system to carry out this study as it An OFET offers various interfaces that can be investigated as it is made up of stacked layers of various material. In order to probe the intrinsic properties that governs the charge transport, we have to be able to carry out thorough investigation of the interactions taking place down at the accumulation layer thickness. However, since organic materials are highly instable in ambient conditions, it becomes quite impossible to investigate the intrinsic properties of the material without the influence of extrinsic factors like air, moisture and light. For this reason, I have employed a technique called the in situ real-time electrical characterization technique which enables electrical characterization of the OFET during the growth of the semiconductor.

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14

Kyndiah, Adrica <1987&gt. « Interfacial interactions, charge transport and growth phenomena in Organic Field Effect Transistors ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7100/.

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Organic electronics is an emerging field with a vast number of applications having high potential for commercial success. Although an enormous progress has been made in this research area, many organic electronic applications such as organic opto-electronic devices, organic field effect transistors and organic bioelectronic devices still require further optimization to fulfill the requirements for successful commercialization. The main bottle neck that hinders large scale production of these devices is their performances and stability. The performance of the organic devices largely depends on the charge transport processes occurring at the interfaces of various material that it is composed of. As a result, the key ingredient needed for a successful improvement in the performance and stability of organic electronic devices is an in-depth knowledge of the interfacial interactions and the charge transport phenomena taking place at different interfaces. The aim of this thesis is to address the role of the various interfaces between different material in determining the charge transport properties of organic devices. In this framework, I chose an Organic Field Effect Transistor (OFET) as a model system to carry out this study as it An OFET offers various interfaces that can be investigated as it is made up of stacked layers of various material. In order to probe the intrinsic properties that governs the charge transport, we have to be able to carry out thorough investigation of the interactions taking place down at the accumulation layer thickness. However, since organic materials are highly instable in ambient conditions, it becomes quite impossible to investigate the intrinsic properties of the material without the influence of extrinsic factors like air, moisture and light. For this reason, I have employed a technique called the in situ real-time electrical characterization technique which enables electrical characterization of the OFET during the growth of the semiconductor.

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15

Genovese, Laura <1987&gt. « Synthesis and Characterization of New Aliphatic Biodegradable Polyesters for Packaging Applications ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7559/1/genovese_laura_tesi.pdf.

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Until now, petrochemical-based plastics have been extensively used as packaging materials thanks to their low cost and excellent physic-mechanical properties. Unfortunately, as it is well-known, these materials are not readily degraded in the environments where they are disposed once their function has ended. As a consequence, thousands of tons of plastic packaging are disposed in landfills every year, causing a continuous pollution increment. In this view, replacing non-degradable plastics based on fossil oil with sustainable bio-based, biodegradable materials for short time applications is of great environmental importance. Among biobased and biodegradable plastic packaging materials, one of the most economically competitive polymer class is represented by aliphatic polyesters, that have attracted considerable attention in last decades as they combine the afore mentioned features with interesting physical and chemical properties. In this framework, the present research work focused on the modification of some interesting aliphatic polyesters, in order to prepare new materials, which guarantee full compostability and offer suitable characteristics, especially in terms of mechanical and barrier properties to be used in food packaging applications. Simple, ecofriendly, cost-effective synthetic strategies have been employed to obtain the designed materials. All the synthesized polymers have been deeply characterized by the molecular, thermal and mechanical point of view. Moreover, their barrier properties have been studied to prove their suitability for packaging applications. Lastly, lab-scale composting experiments have been carried out, in order to check their potential compostability. Solid-state properties and biodegradation rate can be tailored acting on chemical structure, copolymer composition and polymer architecture: in particular, the introduction of different amounts of ether- or thio-ether linkages or short ramifications along macromolecular backbone of parent homopolymer, or simply acting on soft/hard ratio in block structures permitted to modulate mechanical behaviour and biodegradation rate of the parent homopolymer itself, without compromising the good properties.

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16

Genovese, Laura <1987&gt. « Synthesis and Characterization of New Aliphatic Biodegradable Polyesters for Packaging Applications ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7559/.

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Résumé :

Until now, petrochemical-based plastics have been extensively used as packaging materials thanks to their low cost and excellent physic-mechanical properties. Unfortunately, as it is well-known, these materials are not readily degraded in the environments where they are disposed once their function has ended. As a consequence, thousands of tons of plastic packaging are disposed in landfills every year, causing a continuous pollution increment. In this view, replacing non-degradable plastics based on fossil oil with sustainable bio-based, biodegradable materials for short time applications is of great environmental importance. Among biobased and biodegradable plastic packaging materials, one of the most economically competitive polymer class is represented by aliphatic polyesters, that have attracted considerable attention in last decades as they combine the afore mentioned features with interesting physical and chemical properties. In this framework, the present research work focused on the modification of some interesting aliphatic polyesters, in order to prepare new materials, which guarantee full compostability and offer suitable characteristics, especially in terms of mechanical and barrier properties to be used in food packaging applications. Simple, ecofriendly, cost-effective synthetic strategies have been employed to obtain the designed materials. All the synthesized polymers have been deeply characterized by the molecular, thermal and mechanical point of view. Moreover, their barrier properties have been studied to prove their suitability for packaging applications. Lastly, lab-scale composting experiments have been carried out, in order to check their potential compostability. Solid-state properties and biodegradation rate can be tailored acting on chemical structure, copolymer composition and polymer architecture: in particular, the introduction of different amounts of ether- or thio-ether linkages or short ramifications along macromolecular backbone of parent homopolymer, or simply acting on soft/hard ratio in block structures permitted to modulate mechanical behaviour and biodegradation rate of the parent homopolymer itself, without compromising the good properties.

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17

Moncalero, Matteo <1983&gt. « High Performance Polymeric Materials for Sport Equipment, Functional Clothing and Footwear : Interactions of Materials, Human Body and Environment in Terms of Mechanical, Thermal and Ergonomic Properties ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/8127/1/moncalero_matteo_tesi.pdf.

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The study of the influence on mechanical, thermal and ergonomic properties of advanced polymeric materials used to produce outdoors gear and footwear has been the topic of the present PhD thesis. The study has addressed several aspects of ergonomics, safety and mechanical properties of sport equipment: - The evaluation of thermo-physiological comfort of soft-shell back protectors, investigating how design and materials can affect moisture management and heat loss. Heat retention has been identified using infrared thermography. Testers have answered a questionnaire to take into account their subjective sensations. - The effect of liners used in ski boots. Three different ski boot liners have been tested to evaluate the insulating behaviour and the moisture management capability of the materials used. Tests have been conducted in climatic chamber and then repeated in real skiing conditions. Scanning Electron Microscopy has been used to evaluate the effect of cells morphology on thermal insulation. - The effect of different materials used for the production of thermo-formable ski boots have been analysed in order to determine their performance in the process used to adapt the shape of ski boots to the skier’s foot morphology. The effect of foot compression on the thermal comfort has also been evaluated. - The effect of glass fibre/rubber composites on the grip on icy surfaces. The study has been conducted analysing the friction of a ski boot sole containing an insert made of composite material and comparing the results with those obtained using rubber and a thermoplastic elastomer. Scanning Electron Microscopy has been used to perform the morphological analysis of the composite. - Thermal comfort of trekking shoes has been evaluated in climatic chamber using wireless temperature and relative humidity sensors embedded in the midsole. Evaluation of heat retention through the sole and the upper has been performed using thermal imaging.

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18

Carati, Marco <1987&gt. « Handling of molten Poly(ethylene terephthalate) cylinders for preforms compression molding machines ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8372/1/Carati_Marco_Tesi.pdf.

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This thesis describes the research done on the handling of molten Poly(ethylene terephthalate) (PET) cylinders - from now on "gobs" - for preform compression molding, which is a cutting-edge technology in the beverage field. SACMI, a world leading company in manufacturing advanced packaging plants, holds a strong background in compression molding technologies. A new way of handling gobs was investigated, i.e. the pneumatic transport through a swirl flow generated by a particular pipe design. It was developed both with Computational Fluid Dynamic simulations and extensive field tests on a prototypal compression molding machine. The very promising results led SACMI to patent the swirl flow pipe design. A new testing machine was designed and assembled to further develop the tests. The ultimate validation will be on a new compression molding machine prototype. Simultaneously, improved CFD simulations were started to increase pipe efficiency. Moreover, simulations could reduce costs and testing time of new pipe design for different preforms. By comparing the simulation video with a real field test one, a part of the process simulation was validated. Gob adhesiveness to pipe inner walls increased after many gobs passed through the pipe. The cause could be the deposition of a very thin layer of PET oligomers on the pipe wall. Cyclic oligomers, which are dissolved in PET melt, vaporize and then condense on the pipe walls which are colder than the gob. FTIR analyses supported this conclusion. Finally, the effect of metal temperature on gob adhesiveness for short time contact, typical of the preform compression molding technology, was studied and an innovative kind of experiment was designed. A tests campaign was hence performed and led to the description of a new phenomenon for which a theoretical explanation was proposed. These results give a valuable contribution on this topic to the scientific community.

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19

Banella, Maria Barbara <1989&gt. « New strategies for the preparation of high-perfomance bio-based polymers ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8388/1/Banella_MariaBarbara_tesi.pdf.

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Nowadays there is a great interest to substitute petroleum-derived polymers with more sustainable materials. In this thesis the preparation of monomers, polymers and copolymers from renewable resources was carried out, following two strategies. The first one consisted in developing new routes to obtain the traditional polymers from biomass instead that from petroleum. Then, the synthesis of p-toluic acid (the terephthalic acid (TPA) precursor, and monomer for polyethylene terephthalate (PET)) from natural molecules (acrylic and sorbic acids) was set up by exploiting a Diels-Alder (DA) reaction. The developed strategy contributed to a more sustainable production of TPA, and, therefore, of a 100% bio-PET. The second strategy was based on exploiting monomers deriving from biomass to get new polymeric structures. Starting from vanillic acid, a monomer from natural resources, the synthesis of polyethylene vanillate, an homopolymer whose melting and glass transition temperatures are close to those of PET, was set up. To reduce its brittleness, random copolymers with ϵ-polycaprolactone or polyricinoleic acid were prepared; new possible antibacterial functionalities were introduced by ricinoleic acid functionalities. The preparation of copolymers was furthermore studied by considering DA reactions between furans (obtainable from natural resources) and maleimides: a copolymer was prepared by exploiting the tendency by DA adducts located within monomers structures to break over 100°C and to recombine at lower temperatures: the ability to associate and dissociate in a reversible manner can be used to produce innovative self-mending materials. Finally, a compound deriving from vegetal oil biorefinery (dihydroxyacetone) was exploited for obtaining innovative and bio-based polycarbonates and polyesters. In conclusion, strategies to get a 100% bio-PET, new bio-polymers that can substitute PET even with advanced functionalities, innovative bio-copolymers for self-mending materials and new polyesters and polycarbonates making the most of oil biorefinery byproducts were studied.
Nei tempi recenti si è sviluppato un grande interesse nel sostituire polimeri derivati dal petrolio con materiali più sostenibili. In questa tesi si è studiata la possibilità di ottenere da biomassa monomeri, polimeri e copolimeri, seguendo due strategie di sintesi. La prima è consistita nell’ottenimento da biomassa di polimeri tradizionali attualmente ricavati da petrolio. In particolare, la sintesi dell’acido p-toluico (il precursore dell’acido tereftalico (TPA) e, quindi, del polietilene tereftalato (PET)) è stata messa a punto partendo da molecole naturali (dagli acidi sorbico ed acrilico) tramite reazione di Diels-Alder (DA). Ciò ha contribuito ad una produzione più sostenibile del TPA e, pertanto, di un PET bio al 100%. La seconda strategia ha sfruttato monomeri da biomassa per l’ottenimento di nuove strutture polimeriche. Da acido vanillico (un monomero da fonti naturali) è stata messa a punto la sintesi del polietilene vanillato, un omopolimero le cui temperature di fusione e transizione vetrosa sono vicine a quelle del PET. Al fine di ridurne la fragilità, sono stati preparati polimeri statistici con unità di ϵ-policaprolattone o di acido poliricinoileico, dalle cui funzionalità sono state introdotte nuove possibili proprietà antibatteriche. La preparazione di copolimeri è stata inoltre studiata tramite reazioni DA fra furani (ottenibili da fonti naturali) e malemmidi; un copolimero è stato preparato sfruttando la tendenza degli addotti DA presenti all’interno della struttura monomerica di rompersi sopra 100°C e di ricombinarsi a temperature inferiori; l’abilità di associarsi e dissociarsi reversibilmente può essere usata per produrre materiali autoriparanti innovativi. Infine un composto proveniente dalla bioraffineria degli oli vegetali (diidrossiacetone) è stato utilizzato per ottenere bio-policarbonati e bio-poliesteri. Concludendo, sono state studiate strategie per ottenere un PET 100% bio, nuovi bio-polimeri che possano sostituirlo addirittura con proprietà avanzate, bio-polimeri per materiali autoriparanti e poliesteri e policarbonati sfruttando al meglio sottoprodotti della bioraffineria degli oli vegetali.

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Guidotti, Giulia <1989&gt. « Design of new biopolymers for biomedicine and food-packaging ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8892/2/Guidotti_Giulia_Tesi.pdf.

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The limited fossil fuels reserves, as well as serious pollution problems, have led to a continuously growing interest in the use of sustainable materials obtained from renewable sources for many different applications. Among these materials, biopolymers, and in particular the class of biopolyesters, could potentially replace traditional plastics. Their versatility and their ability to undergo degradation in the environment where they are disposed, is of particular interest both for food packaging (when recycling is not possible due to organic matter contamination as well as multi-layered structures) and for biomedicine, in case of temporary applications, such as controlled drug release or tissue engineering. If these materials hydrolyse in the human body, it is possible to avoid the removal of the implant through surgery. In this framework, aim of the present research project was the synthesis and characterization of new bio-based and biodegradable polyesters and copolyesters, with tailored properties in relation to the intended use, in the fields of food packaging, which is one of the most demanding in terms of plastic sources, and regenerative medicine, as it represents the new frontier of biomedicine. The synthetic routes adopted (i.e. two-step melt polycondensation, ring opening polymerization and chain extension) are solvent-free, simple and economic, and can be easily used for industrial scale-up. Monomers from renewable sources were preferred over the ones obtained from fossil fuels. Moreover, copolymerization turned out to be a winning strategy to modify the polymers of interest. Starting from polyesters, the aliphatic (i.e. polylactic acid, poly(butylene succinate), polymers containing cyclohexane ring) and aromatic ones (i.e. polymers containing furan and thiophene rings), all characterized by high stiffness and low degradation rates, it was possible to obtain more flexible materials with higher biodegradation rates, particularly suitable for soft tissue engineering and for the realization of flexible food packaging films.

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Marcolongo, Alberto <1987&gt. « Development of innovative processes for the transformation of polymeric thermoplastic materials based on compression molding at high rates ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8909/3/Marcolongo_Alberto_tesi.pdf.

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Poly(lactic acid) possesses many desirable properties, above all biodegradability an compostability. PLA can be either amorphous or semicrystalline depending on its stereochemistry and thermal history. A high crystallinity degree is desirable to increase the heat resistance of PLA but it is rather difficult to reach high values during injection and compression moulding due to its very slow crystallization kinetics. Therefore, two different approaches can be carried out. The first concerns the synthesis and use of a PLA stereocomplex by mixing PLLA and PDLA, because this blend has shown higher crystallization rates and higher melting temperature than the single homopolymers. The second approach regards the adding of a nucleating agent that favours the formation of the PLA spherulites. In my thesis project, funded by SACMI Imola, an innovative process for the processing of PLA by compression moulding was developed. The study was focused on two different aspects. The first regarded the formation and crystallization of the stereocomplex by means a Rheo-Raman instrument. The second aspect regarded the investigation of some operative parameters for the compression moulding process for the production of coffee-pods. The results regarding the stereocomplex have shown that its formation is strongly affected from two different parameters that are the temperature of the experiment and the shear rate applied. By means the Rheo-Raman analysis it was also possible to monitor on line the formation and crystallization of the stereocomplex, that takes place in relatively short time (1-2 minutes). As far as the processing of PLA by means compression moulding is concerned, the attention was focused on the thermal treatments after the formation of the coffee pod. This thermal treatment, carried out by means a post-mould device, favours the post crystallization process of the polymer leading to reach the target value requested for the application in the coffee machines.

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Quattrosoldi, Silvia <1993&gt. « New bio-based polymers : from synthesis to characterization ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9597/4/Quattrosoldi_Silvia_tesi.pdf.

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The environmental problems caused by human activity are one of the main themes of debate of the last Century. As regard plastics, the use of non-renewable sources together with the accumulation of waste in natural habitats are causing serious pollution problems. For this reason, a continuously growing interest is recorded around sustainable materials, potential candidate for the replacement of traditional recalcitrant plastics. Promising results have been obtained with biopolymers, in particular with the class of biopolyesters. Their potential biodegradability and biobased nature is particularly interesting mainly for food packaging, where the multilayer systems normally used and the contamination by organic matter create severe recycling limits. In this framework, the present research has been conducted with the aim of synthetizing, modifying and characterizing biopolymers for food packaging application. New bioplastics based on monomers derived from renewable resources were successfully synthetized by two-step melt polycondensation and chain extension reaction following the “Green chemistry” principles. Moreover, well-known biopolyesters have been modified by blending or copolymerization, both resulting effective techniques to ad hoc tune the polymer final characteristics. The materials obtained have been processed and characterized from the chemical, structural, thermal and mechanical point of view; more specific characterizations as compostability tests, surface hydrophilicity film evaluation and barrier property measurements were conducted.

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Simonini, Emanuele <1989&gt. « Bio-plastics and technologies for eco-sustainable packaging ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9698/1/Tesi%20Dottorato%20Emanuele%20Simonini%20AMS%20Thesis.pdf.

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Transmission welding tests on different eco-sustainable materials were performed using Thulium fiber laser radiation with 2 μm wavelength. All the samples were characterized via infra-red spectroscopy and DSC. The morphology of the materials and the relations between the laser process conditions and the quality of the seam were investigated by means of optical microscopy. Mechanical strength of the weld joints were measured via tensile tests, comparing some of them with different sealing methods and/or original tensile properties of the materials. The morphology of the non-woven material especially plays an important role, compared to the continuous films, as well as the chemical nature of the samples. The experiments demonstrate new application areas of mid-IR fiber laser sources for materials processing.

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Giacobazzi, Greta <1993&gt. « Preparation and characterization of multifunctional bio-based polymers exhibiting enhanced properties ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9717/5/Giacobazzi_Greta_tesi.pdf.

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Driven by environmental reasons and the expected depletion of crude oil, bio-based polymers are currently undergoing a renaissance in the attempt to replace fossil-based ones. The present work aims at contributing in the development of the steps that start from biomass and move to new polymeric multifunctional materials. The study focuses on two bio-based building blocks (itaconic and vanillic acids) characterized by exploitable functionalities, i.e. a lateral double bond and a substituted aromatic ring respectively, able to confer interesting properties to the final polymers. The lateral double bond of dimethyl itaconate was functionalized via thia-Michael addition reaction obtaining a thermo-stable building block that can undergo polycondensation under classical conditions of reaction. The addition of a long lateral chain allows the polymer to express antimicrobial activity against Staphylococcus aureus making it attractive for packaging and targeting antimicrobial applications. Moreover, the architecture of the homopolymer was modified by means of copolymerization with dimethyl 2,5-furandicarboxylate thus improving the rigidity and obtaining a thermo-processable material. Potential applications as thermoset or thermoplastic material have been discussed. As concerns vanillic acid, the presence of aromatic rings on the polymer backbone imparts high thermal stability, but brittle behaviour in the homopolymer. Therefore, the architecture of the polyester was successfully tuned by means of copolymerization with a flexible bio-based comonomer, i.e. ω-pentadecalactone, providing processable random copolymers. An in depth investigation of water transport mechanism has been undertaken on the synthesized polyesters. Since the copolymers present a succession of aromatic and aliphatic units, as a consequence of the chemical structure water vapor permeability interposes between polyethylene and poly(ethylene terephthalate) proving that the copolyesters are suitable for packaging applications. Moving towards a sustainable model of development, novel sustainable synthetic pathways for the eco-design of new bio-based polymeric structures with high value functionalities and different potential applications have been successfully developed.

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TROVATO, Valentina. « Design and development of electroconductive and stimuli-responsive coatings for wearable smart textiles ». Doctoral thesis, Università degli studi di Bergamo, 2020. http://hdl.handle.net/10446/181513.

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IACOBONI, ILARIA. « Inclusione di materiali bidimensionali (2D) in matrici polimeriche ». Doctoral thesis, Università degli Studi dell'Aquila, 2021. http://hdl.handle.net/11697/182253.

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This work focuses on the inclusion of montmorillonite(MMT) and reduced graphene oxide (2D nanomaterials) in polyamide-imide(PAI) matrices. The challenge was to find specific methods to obtain a polymer nanocomposite with better and/or alternatives features compared to the standard polymer. PAI in general exhibits properties which can be attributed to the class of high-performance enamels. The effect of the nanomaterial inclusions on chemical resistance, thermal, mechanical and electric properties was investigated after a specific industrial application: magnet wire coating. For this purpose, nanocomposites were coated on the surface of copper wires and cured to form an electrical insulation film. In literature, several methods for a variety of polymer systems were widely investigated, except for PAI, on which there has been little research. Furthermore, the use of nanomaterials in polymeric matrices for copper wire applications still remains an unexplored field. In order to obtain polymer nanocomposite, two different methods have been used in this work: the solvent casting method and in situ polymerization. After the characterization of the 2D nanomaterials and the polymer, the first part of this thesis dealt with the nanocomposites synthesis of PAI-MMT modified with cationic surfactants of alkylammonium type [benzyl (hydrogenated tallow alkyl) dimethyl ammonium]. Surfactants provide an organophilic character to the silicates through a surface functionalization able to provide a good interaction with hydrophobic polymers. The introduction of groups characterized by a greater steric hindrance also has the advantage of spacing the platelets, facilitating the subsequent incorporation of the macromolecules. The physical separation of the silicate layers is an aspect of extreme importance, since only when completely exfoliated, nanocomposite can offer all its peculiar properties. In situ polymerization was performed by swelling MMT intergalleries with trimellitic anhydride (TMA) monomers followed by addition of MDI and subsequent polymerization to PAI within the intergalleries. The solvent casting method is based on swelling MMT intergalleries with solvent where the polymer is soluble (NMP in this case). Mixing of polymer and layered nanomaterial solutions results in intercalation of polymer chains and displacement of the solvent within the interlayers of silicates. With the approach of in situ polymerization, a new level of exfoliated particle concentration could be reached but in comparison, the solvent casting method turned out to be simpler and faster. In the second part of this work, reduced graphene oxide (rGO) was used instead of organoclay. The two methods previously described were also used for the synthesis of rGO-PAI nanocomposites. With in situ polymerization, a novel approach toward PAI-PE-rGO hybrid system (where PE indicates polyester) was developed. For this purpose, first rGO was covalently linked to the polyester (through the reaction with a dialcohol and a diacid in a 1:2 ratio, obtaining a polyester with terminal acid groups), then the PAI component was synthesized using these groups for the amide formation by reaction with MDI (methylenediphenyldiisocyanate). The success of covalent linking between rGO and polymer matrix was confirmed by the analysis of the acid number using the potentiometric method and FTIR. The MMT-PAI and rGO-PAI resins were then applied to the copper wire on which the control tests were performed. The last part of this dissertation focused on the synthesis of PAI-rGO nanocomposites (by solvent casting method) at different concentrations in order to obtain a light conductive resin. Even if a typical property of this kind of polymer is a good electrical insulation, it could be useful, for some applications, obtaining conductive properties. Subsequently, the varnishes were applied by means of a film applicator on tin-plate sheets and observed through an optical microscope and SEM.

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DUCOLI, SERENA. « Development of new reference nanomaterials for environmental plastic pollution and assessment of interactions with biological systems ». Doctoral thesis, Università degli studi di Brescia, 2022. http://hdl.handle.net/11379/558641.

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Comprendere l'impatto delle micro- e nanoplastiche sugli ecosistemi sta diventando sempre più importante, come evidenziato dalla crescita esponenziale della letteratura scientifica riguardante questi inquinanti. Le nanoplastiche si formano in ambiente a causa di processi naturali di degradazione dei rifiuti plastici. Tuttavia, i campioni ambientali sono difficili da gestire, a causa della loro complessità, eterogeneità e dell'alto livello di impurità naturali. Per questo motivo, la gran parte degli studi condotti finora si basa sull’utilizzo di nanoparticelle sintetiche, come modelli delle nanoplastiche naturali. Inoltre, quasi tutti gli studi pubblicati si basano su nanoparticelle di polistirene; tuttavia, è verosimile ritenere che le nanoplastiche naturalmente formate in ambiente derivino da una varietà di rifiuti plastici. È necessario creare nanomateriali che meglio rispecchino le caratteristiche delle nanoplastiche naturalmente formate, per colmare il divario tra la pratica di laboratorio e le regole della natura e per fornire una comprensione più realistica delle caratteristiche delle nanoplastiche. In questa tesi viene proposto un nuovo nanomateriale di riferimento per lo studio delle nanoplastiche ambientali, nominato “true-to-life nanoplastics” (T2LNPs), ottenuto per frammentazione meccanica in condizioni criogeniche di oggetti plastici di uso quotidiano. Nel Capitolo 1 viene descritto l’ambito di questo progetto di ricerca, ovvero l’inquinamento ambientale da plastica e i processi di degradazione che portano alla formazione di microplastiche e nanoplastiche. Viene anche presentato lo stato dell’arte riguardante lo studio delle nanoplastiche. Nel Capitolo 2 viene descritto il protocollo sviluppato in questo studio per la produzione di “T2LNPs” di polistirene, mediante frammentazione meccanica. Viene inoltre presentata una caratterizzazione morfologica e fisico-chimica dei campioni prodotti. Nel Capitolo 3 vengono discusse le prove preliminari condotte per la quantificazione dei campioni. Nel Capitolo 4 vengono presentati i risultati dello studio sull’interazione biologica dei campioni di “T2LNPs” in confronto alle nanoparticelle sintetiche di polistirene. Nel Capitolo 5 viene presentato lo studio sulla produzione e caratterizzazione di campioni “T2LNPs” di polietilene tereftalato (PET) e poliammide 66 (PA66), condotto adattando i protocolli sviluppati per lo studio del polistirene, comprensivi di frammentazione meccanica, caratterizzazione morfologica e fisico-chimica e studio delle interazioni biologiche. Il capitolo 6 riassume i principali risultati di questo lavoro di ricerca e introduce gli sviluppi e le prospettive futuri. A complemento dello studio sui materiali di riferimento per le nanoplastiche, durante il periodo di dottorato sono stati anche condotti studi relativi alla valutazione della sostenibilità di nuovi processi/materiali. Tali valutazioni, in parte correlate all’ambito principale della tesi, sono discusse in appendice alla tesi. Nell'Appendice A vengono brevemente introdotti i concetti di valutazione della sostenibilità ed economia circolare e viene proposto un nuovo strumento, denominato ESCAPE, per la valutazione precoce della sostenibilità di un nuovo materiale, nelle fasi di ricerca e sviluppo. Nell'Appendice B vengono discussi tre studi “proof-of-concept” per validare il metodo ESCAPE. Questo lavoro nasce da una collaborazione interdisciplinare tra il Laboratorio di Chimica per le Tecnologie DIMI, e il Laboratorio di Biochimica clinica e Biologia molecolare clinica DMMT, dell'Università degli Studi di Brescia. La ricerca è stata finanziata dal PON “R&I” 2014-2020: SIRIMAP—SIstemi di Rilevamento dell'Inquinamento MArino da Plastiche e successivo recupero-riciclo (N. ARS01_01183, CUP D86C18000520008) ed è in parte basata su COST Action CA20101 Plastics monitoring detectioniOn RemedIaTION recovery - PRIORITY.
Understanding the impact of micro and nanoplastics on the environment and the living organisms is becoming increasingly pressing, as highlighted by the exponential growth of literature regarding these pollutants. Nanoplastics form in the environment due to natural degradation processes of plastic wastes, such as photodegradation, mechanical fragmentation and biodegradation. However, environmental samples are difficult to manage, because of the extremely complexity, heterogeneity and the high level of natural impurities. For this reason, to date fundamental studies are mostly conducted by using model synthetic nanobeads, instead of natural nanoplastics. Moreover, almost all literature available on nanobeads is based on polystyrene nanobeads; however, nanoplastics in the environment are expected to derive from a variety of waste polymers. There is the need to create nanomaterials that better reflect the real characteristics of nanoplastics naturally formed, to close the gap between the laboratory practice and the rules of nature, and to provide more realistic understandings of the characteristics of nanoplastics. In this thesis, plastic nanoparticles obtained by mechanical fragmentation in cryogenic conditions of daily-life plastic items, “true-to-life” nanoplastics (T2LNPs), are proposed as a better reference nanomaterial for the study of environmental nanoplastics. Chapter 1 outlines the topic of the research project, related to the environmental plastic pollution and the degradation processes that lead to the formation of microplastics and nanoplastics. The state of the art in the study of nanoplastics is also discussed. In Chapter 2, the developed protocol for the production of polystyrene T2LNPs by means of mechanical fragmentation is described. A complete morphological and physical–chemical characterization of PS-T2LNPs is presented. In Chapter 3, preliminary tests for the quantification of PS-T2LNPs are discussed. Chapter 4 presents the investigation of PS-T2LNPs behavior at the biological interface, in comparison to the behavior of polystyrene nanobeads. Chapter 5 focuses on polymeric materials different from polystyrene. T2LNPs of polyethylene terephthalate (PET) and polyamide 66 (PA66) are produced and characterized adapting the protocols developed for polystyrene, including mechanical fragmentation, morphological and physical–chemical characterization and the investigation of biological interactions. Chapter 6 summarizes the principal results of the research work and introduces future developments and perspectives. Complementary activities regarding the sustainability evaluation of new processes / materials have also been conducted during the PhD period. These evaluations, partially related to the main core of PhD research, are discussed in the Appendix of the thesis. Appendix A briefly discusses the concepts of sustainability evaluation and circular economy and presents a new tool, named ESCAPE, for early sustainability assessment of new materials, at research and development stages. Appendix B discusses three proof-of-concept studies of the proposed ESCAPE tool. This work is framed in an interdisciplinary collaboration between the Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, and the Clinical Biochemistry and Clinical Molecular Biology Laboratory, Department of Molecular and Translational Medicine, of the University of Brescia. The research was funded by PON “R&I” 2014-2020: SIRIMAP—SIstemi di Rilevamento dell’Inquinamento MArino da Plastiche e successivo recupero-riciclo (No. ARS01_01183, CUP D86C18000520008) and partially based upon work from COST Action CA20101 Plastics monitoRIng detectiOn RemedIaTion recoverY - PRIORITY, supported by COST (European Cooperation in Science and Technology). www.cost.eu.

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DUCOLI, SERENA. « Development of new reference nanomaterials for environmental plastic pollution and assessment of interactions with biological systems ». Doctoral thesis, Università degli studi di Brescia, 2022. http://hdl.handle.net/11379/558645.

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Résumé :

Comprendere l'impatto delle micro- e nanoplastiche sugli ecosistemi sta diventando sempre più importante, come evidenziato dalla crescita esponenziale della letteratura scientifica riguardante questi inquinanti. Le nanoplastiche si formano in ambiente a causa di processi naturali di degradazione dei rifiuti plastici. Tuttavia, i campioni ambientali sono difficili da gestire, a causa della loro complessità, eterogeneità e dell'alto livello di impurità naturali. Per questo motivo, la gran parte degli studi condotti finora si basa sull’utilizzo di nanoparticelle sintetiche, come modelli delle nanoplastiche naturali. Inoltre, quasi tutti gli studi pubblicati si basano su nanoparticelle di polistirene; tuttavia, è verosimile ritenere che le nanoplastiche naturalmente formate in ambiente derivino da una varietà di rifiuti plastici. È necessario creare nanomateriali che meglio rispecchino le caratteristiche delle nanoplastiche naturalmente formate, per colmare il divario tra la pratica di laboratorio e le regole della natura e per fornire una comprensione più realistica delle caratteristiche delle nanoplastiche. In questa tesi viene proposto un nuovo nanomateriale di riferimento per lo studio delle nanoplastiche ambientali, nominato “true-to-life nanoplastics” (T2LNPs), ottenuto per frammentazione meccanica in condizioni criogeniche di oggetti plastici di uso quotidiano. Nel Capitolo 1 viene descritto l’ambito di questo progetto di ricerca, ovvero l’inquinamento ambientale da plastica e i processi di degradazione che portano alla formazione di microplastiche e nanoplastiche. Viene anche presentato lo stato dell’arte riguardante lo studio delle nanoplastiche. Nel Capitolo 2 viene descritto il protocollo sviluppato in questo studio per la produzione di “T2LNPs” di polistirene, mediante frammentazione meccanica. Viene inoltre presentata una caratterizzazione morfologica e fisico-chimica dei campioni prodotti. Nel Capitolo 3 vengono discusse le prove preliminari condotte per la quantificazione dei campioni. Nel Capitolo 4 vengono presentati i risultati dello studio sull’interazione biologica dei campioni di “T2LNPs” in confronto alle nanoparticelle sintetiche di polistirene. Nel Capitolo 5 viene presentato lo studio sulla produzione e caratterizzazione di campioni “T2LNPs” di polietilene tereftalato (PET) e poliammide 66 (PA66), condotto adattando i protocolli sviluppati per lo studio del polistirene, comprensivi di frammentazione meccanica, caratterizzazione morfologica e fisico-chimica e studio delle interazioni biologiche. Il capitolo 6 riassume i principali risultati di questo lavoro di ricerca e introduce gli sviluppi e le prospettive futuri. A complemento dello studio sui materiali di riferimento per le nanoplastiche, durante il periodo di dottorato sono stati anche condotti studi relativi alla valutazione della sostenibilità di nuovi processi/materiali. Tali valutazioni, in parte correlate all’ambito principale della tesi, sono discusse in appendice alla tesi. Nell'Appendice A vengono brevemente introdotti i concetti di valutazione della sostenibilità ed economia circolare e viene proposto un nuovo strumento, denominato ESCAPE, per la valutazione precoce della sostenibilità di un nuovo materiale, nelle fasi di ricerca e sviluppo. Nell'Appendice B vengono discussi tre studi “proof-of-concept” per validare il metodo ESCAPE. Questo lavoro nasce da una collaborazione interdisciplinare tra il Laboratorio di Chimica per le Tecnologie DIMI, e il Laboratorio di Biochimica clinica e Biologia molecolare clinica DMMT, dell'Università degli Studi di Brescia. La ricerca è stata finanziata dal PON “R&I” 2014-2020: SIRIMAP—SIstemi di Rilevamento dell'Inquinamento MArino da Plastiche e successivo recupero-riciclo (N. ARS01_01183, CUP D86C18000520008) ed è in parte basata su COST Action CA20101 Plastics monitoring detectioniOn RemedIaTION recovery - PRIORITY.
Understanding the impact of micro and nanoplastics on the environment and the living organisms is becoming increasingly pressing, as highlighted by the exponential growth of literature regarding these pollutants. Nanoplastics form in the environment due to natural degradation processes of plastic wastes, such as photodegradation, mechanical fragmentation and biodegradation. However, environmental samples are difficult to manage, because of the extremely complexity, heterogeneity and the high level of natural impurities. For this reason, to date fundamental studies are mostly conducted by using model synthetic nanobeads, instead of natural nanoplastics. Moreover, almost all literature available on nanobeads is based on polystyrene nanobeads; however, nanoplastics in the environment are expected to derive from a variety of waste polymers. There is the need to create nanomaterials that better reflect the real characteristics of nanoplastics naturally formed, to close the gap between the laboratory practice and the rules of nature, and to provide more realistic understandings of the characteristics of nanoplastics. In this thesis, plastic nanoparticles obtained by mechanical fragmentation in cryogenic conditions of daily-life plastic items, “true-to-life” nanoplastics (T2LNPs), are proposed as a better reference nanomaterial for the study of environmental nanoplastics. Chapter 1 outlines the topic of the research project, related to the environmental plastic pollution and the degradation processes that lead to the formation of microplastics and nanoplastics. The state of the art in the study of nanoplastics is also discussed. In Chapter 2, the developed protocol for the production of polystyrene T2LNPs by means of mechanical fragmentation is described. A complete morphological and physical–chemical characterization of PS-T2LNPs is presented. In Chapter 3, preliminary tests for the quantification of PS-T2LNPs are discussed. Chapter 4 presents the investigation of PS-T2LNPs behavior at the biological interface, in comparison to the behavior of polystyrene nanobeads. Chapter 5 focuses on polymeric materials different from polystyrene. T2LNPs of polyethylene terephthalate (PET) and polyamide 66 (PA66) are produced and characterized adapting the protocols developed for polystyrene, including mechanical fragmentation, morphological and physical–chemical characterization and the investigation of biological interactions. Chapter 6 summarizes the principal results of the research work and introduces future developments and perspectives. Complementary activities regarding the sustainability evaluation of new processes / materials have also been conducted during the PhD period. These evaluations, partially related to the main core of PhD research, are discussed in the Appendix of the thesis. Appendix A briefly discusses the concepts of sustainability evaluation and circular economy and presents a new tool, named ESCAPE, for early sustainability assessment of new materials, at research and development stages. Appendix B discusses three proof-of-concept studies of the proposed ESCAPE tool. This work is framed in an interdisciplinary collaboration between the Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, and the Clinical Biochemistry and Clinical Molecular Biology Laboratory, Department of Molecular and Translational Medicine, of the University of Brescia. The research was funded by PON “R&I” 2014-2020: SIRIMAP—SIstemi di Rilevamento dell’Inquinamento MArino da Plastiche e successivo recupero-riciclo (No. ARS01_01183, CUP D86C18000520008) and partially based upon work from COST Action CA20101 Plastics monitoRIng detectiOn RemedIaTion recoverY - PRIORITY, supported by COST (European Cooperation in Science and Technology). www.cost.eu.

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29

FAHIMI, ARIO. « Characterization and sustainability evaluation of phosphorus recovery from incinerated waste streams ». Doctoral thesis, Università degli studi di Brescia, 2022. http://hdl.handle.net/11379/558935.

Texte intégral

Résumé :

Il fosforo (P) è un nutriente vitale e non sostituibile per tutti gli organismi viventi, ma è anche una risorsa non rinnovabile in diminuzione. Il fosforo viene anche estratto principalmente dalla roccia fosfatica per essere applicato come fertilizzante in una popolazione mondiale in continua crescita che richiede un'attività agricola intensiva. Circa i due terzi della fornitura mondiale di roccia fosfatica si trova in Marocco, Cina e Stati Uniti, portando così l'Europa ad avere dipendenza dalle importazioni. Ciò ha portato la Commissione europea a elencare la roccia fosfatica prima nel 2014 e poi il fosforo nel 2017 come materie prime critiche. Da aggiungere che meno del 20% della P utilizzata nei settori della produzione di alimenti e mangimi è consumato da attività antropiche. Concentrandosi sulle maggiori perdite (per lo più associate alla produzione di carne e alle coltivazioni), tra i principali flussi di rifiuti, letame di pollina e fanghi di depurazione rappresentano importanti fonti secondarie di P sotto la Commissione europea e possono aiutare ad alleviare la dipendenza dal fosfato importato. Un modo promettente per recuperare in modo efficiente il P consiste nell'indirizzare i flussi di rifiuti inceneriti (fonti arricchite di P) come potenziale sostituto delle rocce fosfatiche. Pertanto, dato che mancano dati di letteratura sulla caratterizzazione di questo materiale, questa tesi mira a determinare la caratterizzazione comparativa dei residui di ceneri ricchi di P campionati alla combustione a letto fluido di Güres Energy (Turchia) di letame di galline ovaiole e a Campoaves (Portogallo) combustione di griglie a catena di lettiera di pollame di lolla di riso. È stato studiato l'effetto di diversi combustibili e diversi sistemi di combustione sulla speciazione di P nelle ceneri: sono state eseguite la caratterizzazione dei campioni globali (ceneri pesanti (BA), ceneri volanti dell'economizzatore (FAECO), ceneri volanti dei cicloni (FACYC)) e le rispettive frazioni dimensionali chimicamente (analisi approssimata ed elementare mediante fluorescenza a raggi X - XRF - e spettroscopia di massa al plasma accoppiato induttivamente - ICP-MS), morfologicamente (imaging dettagliato e microanalisi a raggi X mediante microscopia elettronica a scansione - spettrometria a raggi X a dispersione di energia - SEM −EDS) e mineralogicamente (diffrazione di raggi X – XRD). Il fosforo è stato rilevato nelle ceneri di Güres principalmente come cristalli di idrossiapatite insieme a reliquie di CaCO3 e CaO, mentre le frazioni di cenere di Campoaves contenevano P anche come fosfato di Na-K-Mg e grandi quantità di reliquie di lolla di riso, tra cui salmerino incombusto e fasi di silice. Sia le ceneri di Güres che quelle di Campoaves sono complesse, ma la combustione del letame di pollina in queste condizioni di impostazione sembra essere promettente per il recupero di P a causa del loro alto contenuto di P e vengono proposte diverse tecniche. Un altro tema principale affrontato in questo lavoro riguarda gli indicatori per la valutazione dell'impatto ambientale. Di seguito viene riportato un approccio semplificato e innovativo, concettualizzato come studio preliminare allo studio del ciclo di vita, per la valutazione della sostenibilità delle nuove tecnologie, basato sull'uso di due parametri (es. energia incorporata e impronta di CO2) che tengono conto dell'energia e delle emissioni coinvolte nella formazione di un materiale. Un indice adimensionale, definito come indice SUB-RAW, confronta i risultati sull'impatto ambientale del materiale/processo sostitutivo selezionato, qua nel contesto delle tecnologie di recupero del P. Lo strumento di valutazione della sostenibilità vuole rappresentare una pietra miliare nella progettazione di strategie per far fronte all'esaurimento delle risorse e suggerire opportunità di evoluzione legislativa, a sostegno di alternative sostenibili alle materie prime.
Phosphorus (P) is a vital and non-substitutable nutrient for all living organisms, but it is also a dwindling non-renewable resource. Phosphorus is also primarily extracted from phosphate rock for being applied as fertilizers in an ever increasing World population demanding intensive agricultural activity. About more than two-thirds of the world’s supply of phosphate rock is located in Morocco, China and the USA leading the European Commission to list phosphate rock first in 2014 and P secondly in 2017 as critical raw materials. To add that, less than 20% of the P used in the food and feed production sectors are anthropogenically consumed. By focusing on the major losses, among the principal waste streams, aviary manure and sewage sludge represent important secondary sources of P under the European Commission and can help alleviate reliance on imported phosphate. A promising way to efficiently recover P is to address incinerated waste streams (P enriched sources) as potential substitute of phosphate rocks. Therefore, since literature data are lacking about characterization and second applications of this material, this thesis aims to determine the comparative characterization of P-rich ash residues sampled at Güres Energy (Turkey) fluidized bed combustion of laying hens manure and at Campoaves (Portugal) chain grate stoker combustion of rice husk poultry litter. The effect of different fuels and different combustion systems on P speciation in ash was investigated: the characterization of global samples (bottom ash (BA), economizer fly ash (FAECO), cyclone fly ash (FACYC)) and respective size-fractions were done chemically (proximate and elemental analysis by X-ray fluorescence – XRF – and Inductively Coupled Plasma Mass Spectroscopy – ICP-MS), morphologically (detailed imaging and X-ray micro analysis by Scanning Electron Microscopy−Energy-Dispersive X-ray spectrometry – SEM−EDS) and mineralogically (X-ray diffraction – XRD). Phosphorus was detected in Güres ashes mainly as hydroxyapatite crystals alongside with CaCO3 relics and CaO, while Campoaves ash fractions contained P also as Na-K-Mg phosphate and major amounts of rice husk relics including unburnt char and silica phases. Both Güres and Campoaves ashes are complex but the combustion of aviary manure under these setting conditions appears to be promising for P recovery owing to their high P content and different techniques are proposed. Another main issue addressed in this work regards indicator for evaluating the environmental impact. Here is reported a simplified and novel approach, conceptualized as preliminary study to Life Cycle Assessment, for sustainability evaluation of new technologies, based on the use of two parameters (i.e. embodied energy and CO2 footprint) that account for the energy and emissions involved in the formation of a material. A dimensionless index, defined as SUB-RAW index, compares the results about the environmental impact of selected substituting material/process, here in the context of P recovery technologies. The sustainability evaluation tool aims to represent a milestone in the design of strategies to cope with resources depletion and to suggest opportunities for legislative evolution, in support of sustainable alternative to raw materials.

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DUCOLI, SERENA. « Development of new reference nanomaterials for environmental plastic pollution and assessment of interactions with biological systems ». Doctoral thesis, Università degli studi di Brescia, 2022. http://hdl.handle.net/11379/558656.

Texte intégral

Résumé :

Comprendere l'impatto delle micro- e nanoplastiche sugli ecosistemi sta diventando sempre più importante, come evidenziato dalla crescita esponenziale della letteratura scientifica riguardante questi inquinanti. Le nanoplastiche si formano in ambiente a causa di processi naturali di degradazione dei rifiuti plastici. Tuttavia, i campioni ambientali sono difficili da gestire, a causa della loro complessità, eterogeneità e dell'alto livello di impurità naturali. Per questo motivo, la gran parte degli studi condotti finora si basa sull’utilizzo di nanoparticelle sintetiche, come modelli delle nanoplastiche naturali. Inoltre, quasi tutti gli studi pubblicati si basano su nanoparticelle di polistirene; tuttavia, è verosimile ritenere che le nanoplastiche naturalmente formate in ambiente derivino da una varietà di rifiuti plastici. È necessario creare nanomateriali che meglio rispecchino le caratteristiche delle nanoplastiche naturalmente formate, per colmare il divario tra la pratica di laboratorio e le regole della natura e per fornire una comprensione più realistica delle caratteristiche delle nanoplastiche. In questa tesi viene proposto un nuovo nanomateriale di riferimento per lo studio delle nanoplastiche ambientali, nominato “true-to-life nanoplastics” (T2LNPs), ottenuto per frammentazione meccanica in condizioni criogeniche di oggetti plastici di uso quotidiano. Nel Capitolo 1 viene descritto l’ambito di questo progetto di ricerca, ovvero l’inquinamento ambientale da plastica e i processi di degradazione che portano alla formazione di microplastiche e nanoplastiche. Viene anche presentato lo stato dell’arte riguardante lo studio delle nanoplastiche. Nel Capitolo 2 viene descritto il protocollo sviluppato in questo studio per la produzione di “T2LNPs” di polistirene, mediante frammentazione meccanica. Viene inoltre presentata una caratterizzazione morfologica e fisico-chimica dei campioni prodotti. Nel Capitolo 3 vengono discusse le prove preliminari condotte per la quantificazione dei campioni. Nel Capitolo 4 vengono presentati i risultati dello studio sull’interazione biologica dei campioni di “T2LNPs” in confronto alle nanoparticelle sintetiche di polistirene. Nel Capitolo 5 viene presentato lo studio sulla produzione e caratterizzazione di campioni “T2LNPs” di polietilene tereftalato (PET) e poliammide 66 (PA66), condotto adattando i protocolli sviluppati per lo studio del polistirene, comprensivi di frammentazione meccanica, caratterizzazione morfologica e fisico-chimica e studio delle interazioni biologiche. Il capitolo 6 riassume i principali risultati di questo lavoro di ricerca e introduce gli sviluppi e le prospettive futuri. A complemento dello studio sui materiali di riferimento per le nanoplastiche, durante il periodo di dottorato sono stati anche condotti studi relativi alla valutazione della sostenibilità di nuovi processi/materiali. Tali valutazioni, in parte correlate all’ambito principale della tesi, sono discusse in appendice alla tesi. Nell'Appendice A vengono brevemente introdotti i concetti di valutazione della sostenibilità ed economia circolare e viene proposto un nuovo strumento, denominato ESCAPE, per la valutazione precoce della sostenibilità di un nuovo materiale, nelle fasi di ricerca e sviluppo. Nell'Appendice B vengono discussi tre studi “proof-of-concept” per validare il metodo ESCAPE. Questo lavoro nasce da una collaborazione interdisciplinare tra il Laboratorio di Chimica per le Tecnologie DIMI, e il Laboratorio di Biochimica clinica e Biologia molecolare clinica DMMT, dell'Università degli Studi di Brescia. La ricerca è stata finanziata dal PON “R&I” 2014-2020: SIRIMAP—SIstemi di Rilevamento dell'Inquinamento MArino da Plastiche e successivo recupero-riciclo (N. ARS01_01183, CUP D86C18000520008) ed è in parte basata su COST Action CA20101 Plastics monitoring detectioniOn RemedIaTION recovery - PRIORITY.
Understanding the impact of micro and nanoplastics on the environment and the living organisms is becoming increasingly pressing, as highlighted by the exponential growth of literature regarding these pollutants. Nanoplastics form in the environment due to natural degradation processes of plastic wastes, such as photodegradation, mechanical fragmentation and biodegradation. However, environmental samples are difficult to manage, because of the extremely complexity, heterogeneity and the high level of natural impurities. For this reason, to date fundamental studies are mostly conducted by using model synthetic nanobeads, instead of natural nanoplastics. Moreover, almost all literature available on nanobeads is based on polystyrene nanobeads; however, nanoplastics in the environment are expected to derive from a variety of waste polymers. There is the need to create nanomaterials that better reflect the real characteristics of nanoplastics naturally formed, to close the gap between the laboratory practice and the rules of nature, and to provide more realistic understandings of the characteristics of nanoplastics. In this thesis, plastic nanoparticles obtained by mechanical fragmentation in cryogenic conditions of daily-life plastic items, “true-to-life” nanoplastics (T2LNPs), are proposed as a better reference nanomaterial for the study of environmental nanoplastics. Chapter 1 outlines the topic of the research project, related to the environmental plastic pollution and the degradation processes that lead to the formation of microplastics and nanoplastics. The state of the art in the study of nanoplastics is also discussed. In Chapter 2, the developed protocol for the production of polystyrene T2LNPs by means of mechanical fragmentation is described. A complete morphological and physical–chemical characterization of PS-T2LNPs is presented. In Chapter 3, preliminary tests for the quantification of PS-T2LNPs are discussed. Chapter 4 presents the investigation of PS-T2LNPs behavior at the biological interface, in comparison to the behavior of polystyrene nanobeads. Chapter 5 focuses on polymeric materials different from polystyrene. T2LNPs of polyethylene terephthalate (PET) and polyamide 66 (PA66) are produced and characterized adapting the protocols developed for polystyrene, including mechanical fragmentation, morphological and physical–chemical characterization and the investigation of biological interactions. Chapter 6 summarizes the principal results of the research work and introduces future developments and perspectives. Complementary activities regarding the sustainability evaluation of new processes / materials have also been conducted during the PhD period. These evaluations, partially related to the main core of PhD research, are discussed in the Appendix of the thesis. Appendix A briefly discusses the concepts of sustainability evaluation and circular economy and presents a new tool, named ESCAPE, for early sustainability assessment of new materials, at research and development stages. Appendix B discusses three proof-of-concept studies of the proposed ESCAPE tool. This work is framed in an interdisciplinary collaboration between the Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, and the Clinical Biochemistry and Clinical Molecular Biology Laboratory, Department of Molecular and Translational Medicine, of the University of Brescia. The research was funded by PON “R&I” 2014-2020: SIRIMAP—SIstemi di Rilevamento dell’Inquinamento MArino da Plastiche e successivo recupero-riciclo (No. ARS01_01183, CUP D86C18000520008) and partially based upon work from COST Action CA20101 Plastics monitoRIng detectiOn RemedIaTion recoverY - PRIORITY, supported by COST (European Cooperation in Science and Technology). www.cost.eu.

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31

FAHIMI, ARIO. « Characterization and sustainability evaluation of phosphorus recovery from incinerated waste streams ». Doctoral thesis, Università degli studi di Brescia, 2022. http://hdl.handle.net/11379/558937.

Texte intégral

Résumé :

Il fosforo (P) è un nutriente vitale e non sostituibile per tutti gli organismi viventi, ma è anche una risorsa non rinnovabile in diminuzione. Il fosforo viene anche estratto principalmente dalla roccia fosfatica per essere applicato come fertilizzante in una popolazione mondiale in continua crescita che richiede un'attività agricola intensiva. Circa i due terzi della fornitura mondiale di roccia fosfatica si trova in Marocco, Cina e Stati Uniti, portando così l'Europa ad avere dipendenza dalle importazioni. Ciò ha portato la Commissione europea a elencare la roccia fosfatica prima nel 2014 e poi il fosforo nel 2017 come materie prime critiche. Da aggiungere che meno del 20% della P utilizzata nei settori della produzione di alimenti e mangimi è consumato da attività antropiche. Concentrandosi sulle maggiori perdite (per lo più associate alla produzione di carne e alle coltivazioni), tra i principali flussi di rifiuti, letame di pollina e fanghi di depurazione rappresentano importanti fonti secondarie di P sotto la Commissione europea e possono aiutare ad alleviare la dipendenza dal fosfato importato. Un modo promettente per recuperare in modo efficiente il P consiste nell'indirizzare i flussi di rifiuti inceneriti (fonti arricchite di P) come potenziale sostituto delle rocce fosfatiche. Pertanto, dato che mancano dati di letteratura sulla caratterizzazione di questo materiale, questa tesi mira a determinare la caratterizzazione comparativa dei residui di ceneri ricchi di P campionati alla combustione a letto fluido di Güres Energy (Turchia) di letame di galline ovaiole e a Campoaves (Portogallo) combustione di griglie a catena di lettiera di pollame di lolla di riso. È stato studiato l'effetto di diversi combustibili e diversi sistemi di combustione sulla speciazione di P nelle ceneri: sono state eseguite la caratterizzazione dei campioni globali (ceneri pesanti (BA), ceneri volanti dell'economizzatore (FAECO), ceneri volanti dei cicloni (FACYC)) e le rispettive frazioni dimensionali chimicamente (analisi approssimata ed elementare mediante fluorescenza a raggi X - XRF - e spettroscopia di massa al plasma accoppiato induttivamente - ICP-MS), morfologicamente (imaging dettagliato e microanalisi a raggi X mediante microscopia elettronica a scansione - spettrometria a raggi X a dispersione di energia - SEM −EDS) e mineralogicamente (diffrazione di raggi X – XRD). Il fosforo è stato rilevato nelle ceneri di Güres principalmente come cristalli di idrossiapatite insieme a reliquie di CaCO3 e CaO, mentre le frazioni di cenere di Campoaves contenevano P anche come fosfato di Na-K-Mg e grandi quantità di reliquie di lolla di riso, tra cui salmerino incombusto e fasi di silice. Sia le ceneri di Güres che quelle di Campoaves sono complesse, ma la combustione del letame di pollina in queste condizioni di impostazione sembra essere promettente per il recupero di P a causa del loro alto contenuto di P e vengono proposte diverse tecniche. Un altro tema principale affrontato in questo lavoro riguarda gli indicatori per la valutazione dell'impatto ambientale. Di seguito viene riportato un approccio semplificato e innovativo, concettualizzato come studio preliminare allo studio del ciclo di vita, per la valutazione della sostenibilità delle nuove tecnologie, basato sull'uso di due parametri (es. energia incorporata e impronta di CO2) che tengono conto dell'energia e delle emissioni coinvolte nella formazione di un materiale. Un indice adimensionale, definito come indice SUB-RAW, confronta i risultati sull'impatto ambientale del materiale/processo sostitutivo selezionato, qua nel contesto delle tecnologie di recupero del P. Lo strumento di valutazione della sostenibilità vuole rappresentare una pietra miliare nella progettazione di strategie per far fronte all'esaurimento delle risorse e suggerire opportunità di evoluzione legislativa, a sostegno di alternative sostenibili alle materie prime.
Phosphorus (P) is a vital and non-substitutable nutrient for all living organisms, but it is also a dwindling non-renewable resource. Phosphorus is also primarily extracted from phosphate rock for being applied as fertilizers in an ever increasing World population demanding intensive agricultural activity. About more than two-thirds of the world’s supply of phosphate rock is located in Morocco, China and the USA leading the European Commission to list phosphate rock first in 2014 and P secondly in 2017 as critical raw materials. To add that, less than 20% of the P used in the food and feed production sectors are anthropogenically consumed. By focusing on the major losses, among the principal waste streams, aviary manure and sewage sludge represent important secondary sources of P under the European Commission and can help alleviate reliance on imported phosphate. A promising way to efficiently recover P is to address incinerated waste streams (P enriched sources) as potential substitute of phosphate rocks. Therefore, since literature data are lacking about characterization and second applications of this material, this thesis aims to determine the comparative characterization of P-rich ash residues sampled at Güres Energy (Turkey) fluidized bed combustion of laying hens manure and at Campoaves (Portugal) chain grate stoker combustion of rice husk poultry litter. The effect of different fuels and different combustion systems on P speciation in ash was investigated: the characterization of global samples (bottom ash (BA), economizer fly ash (FAECO), cyclone fly ash (FACYC)) and respective size-fractions were done chemically (proximate and elemental analysis by X-ray fluorescence – XRF – and Inductively Coupled Plasma Mass Spectroscopy – ICP-MS), morphologically (detailed imaging and X-ray micro analysis by Scanning Electron Microscopy−Energy-Dispersive X-ray spectrometry – SEM−EDS) and mineralogically (X-ray diffraction – XRD). Phosphorus was detected in Güres ashes mainly as hydroxyapatite crystals alongside with CaCO3 relics and CaO, while Campoaves ash fractions contained P also as Na-K-Mg phosphate and major amounts of rice husk relics including unburnt char and silica phases. Both Güres and Campoaves ashes are complex but the combustion of aviary manure under these setting conditions appears to be promising for P recovery owing to their high P content and different techniques are proposed. Another main issue addressed in this work regards indicator for evaluating the environmental impact. Here is reported a simplified and novel approach, conceptualized as preliminary study to Life Cycle Assessment, for sustainability evaluation of new technologies, based on the use of two parameters (i.e. embodied energy and CO2 footprint) that account for the energy and emissions involved in the formation of a material. A dimensionless index, defined as SUB-RAW index, compares the results about the environmental impact of selected substituting material/process, here in the context of P recovery technologies. The sustainability evaluation tool aims to represent a milestone in the design of strategies to cope with resources depletion and to suggest opportunities for legislative evolution, in support of sustainable alternative to raw materials.

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32

LAGANA', GIUSEPPINA. « Dental anomalies : retrospective radiographic study in a large sample of non-orthodontic subjects ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2015. http://hdl.handle.net/2108/201883.

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33

DOMAKOSKI, ANA CAROLINA. « Impiego di un array di sensori di gas e di tecniche gascromatografiche per lo studio di patologie e forme cellulari attraverso l'analisi di composti volatili rilasciati dai fluidi biologici ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2016. http://hdl.handle.net/2108/201857.

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The present thesis describes the potentials that the volatile organic compounds (VOCs) have in diagnostics as well as the results achieved by using innovative analytical systems (such as SPME-GC/MS spectrometer and electronic nose instruments) to reveal pathologies, inflammatory processes, metabolic disorders, infections and degenerative cellular processes, also occurring in the early stages. Therefore, in collaboration with both clinicians and research groups of medicine and biology, chemistry and electronic engineering, three different experiments were carried out and here described. The first one was related to the application of both a homemade electronic nose (Department of Electronic Engineering of “Tor Vergata” University), based quartz crystal microbalances (QCM) differently coated with metal porphyrins (synthesized in the Laboratory of Chemistry of “Tor Vergata” University), and a SPME-GC/MS spectrometer to investigate the pattern of the volatile compounds of synovial fluids coming from several patients suffering from two different knee‟s rheumatic diseases (“Tor Vergata” General Hospital, Medicine Department). In this case a greater abundance of volatile compounds in OA than RA. The biomarkers for differential diagnosis between OA and RA are still defective. Through the analysis of the head space of the synovial fluid by NE, good discrimination was obtained between the different pathologies considered the results indicate that the VOC mixture in the synovial fluid of patients with OA is different from that of patients with RA. The second one involved a similar equipment, whereas the electronic nose contained an increased number of sensors, to investigate VOCs from living mice (i.e. breath, skin, urine, faeces) infected with erythrocytes containing different strains of plasmodium (Higher Health Institute, ISS). The results by Plasmodium berghei infection alters the profile of VOCs released, NE analysis of the entire murine volatiloma has led to a good discrimination between a group of healthy mice and one of malaria-affected rats. The GC/MS was detected by a set of VOCs whose concentration was statistically different between infected and uninfected mice. The last one provided an intriguing investigation, using the same instrumentation, on the pattern of volatile compounds from stem cell (specifically Induced Pluripotent Stem cell) in the different stages of differentiation (Department of Genetics). In each application, a suitable measurement protocol was arranged. All the results were treated with statistical analysis and multicomponent analysis. The results support the hypothesis that the volatile fraction of the metabolic profile changes along the differentiation process as a reflection of the variations occurring in the cells. The GC/MS shows a number of compounds that can discriminate between the various stages of differentiation. The NE shows good ability to discriminate between different cellular stages, from pluripotency to differentiated cells.

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RANI, MONIKA. « Analysis and Characterization of Microplastics through Vibrational Spectroscopic Techniques for Environmental Monitoring ». Doctoral thesis, Università degli studi di Brescia, 2022. http://hdl.handle.net/11379/563081.

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The pinnacle of technological advancements, especially plastic, has become one of the greatest environmental challenges that the earth has ever dealt with. In the face of ground-breaking versatility, plastic litter has marked its presence from the highest peaks to the deepest points in the oceans. Microplastics (MPs) are plastic particles with a size of less than 1 mm along their longest dimension, originating from a wide array of sources. The current public awareness of MP pollution is based on a huge amount of scientific research completed and published over the last fifteen years, which has just recently been highlighted by the media. It's been a protracted process that began with isolated examinations carried out by researchers who were ordinarily working in various fields of study but recognised the threat's potential. MPs are not traditional chemical contaminants, but rather a complex array of manmade detritus made up of various sizes, polymers, chemical additives, and sorbed pollution. The MP study is still in its infancy stage since it continues to be hampered by a lack of defined protocols and methodologies for investigating MPs in the laboratory. The use of MPs in laboratory research necessitates precise particle characterization to link the impacts of microplastics to their characteristics. To understand microplastic transit, deposition, and toxic effects, it is vital to distinguish between MP particles and those that are not. This thesis has primarily focused on the application of a new technology for analyzing MPs, based on Near-Infrared Spectroscopy (NIRs). As revealed by the bibliometric analysis of characterizing MPs by Fourier-Transformation Infrared Spectroscopy (FTIR) and Near-Infrared Spectroscopy, NIRs have only lately been applied, notably in the form of the miniaturized spectrometer (NIRs). Although NIR spectroscopy has been used as a standard tool for online quality assurance in food manufacturing and pharmaceuticals for decades, its ability to analyse microplastics in various environmental matrices has only recently been recognized. The workflow of this thesis begins with the use of handheld MicroNIR to analyse urban plastic garbage and construct an in-house NIR spectrum library, showcasing the usage of portable technology in the recycling sector. Because most libraries are constructed with virgin polymers, spectral shifts caused by MPs degradation are frequently missed. As a result, a new, more durable library searching algorithm capable of dealing with the difficulty of comparing degraded MPs to pristine polymer references was necessary. The second section discussed the significance of using reference materials in MP research and compares three techniques for producing MPs for research laboratories. This work will make it easier to comprehend the morphologies of MPs produced from the same parent particle using diverse techniques in a short period, allowing MP research to accelerate. The third section is based on the proof-of-concept study to analyse mixtures of microplastics through a handheld Near-Infrared Spectrometer. Given that, this study has proven the possibility of a portable tiny near-infrared spectrometer (MicroNIR) paired with chemometric methodologies for the measurement of secondary MPs mixes created at a laboratory scale for the first time. Extraction and purification are followed by identification and quantification in the MP analysis. The extraction of MPs from any environmental matrix is the most important phase since it is controlled by the matrix type and microplastic's size, shape, and density. As a result, the extraction technique should be tailored to the type of matrix under consideration. Following this idea, a comprehensive description of microplastic extraction processes distinguished by environmental matrix is offered at the end of this thesis in the form of a review. With concluding remarks, the final chapter gives a glimpse into the study's future prospects.
The pinnacle of technological advancements, especially plastic, has become one of the greatest environmental challenges that the earth has ever dealt with. In the face of ground-breaking versatility, plastic litter has marked its presence from the highest peaks to the deepest points in the oceans. Microplastics (MPs) are plastic particles with a size of less than 1 mm along their longest dimension, originating from a wide array of sources. The current public awareness of MP pollution is based on a huge amount of scientific research completed and published over the last fifteen years, which has just recently been highlighted by the media. It's been a protracted process that began with isolated examinations carried out by researchers who were ordinarily working in various fields of study but recognised the threat's potential. MPs are not traditional chemical contaminants, but rather a complex array of manmade detritus made up of various sizes, polymers, chemical additives, and sorbed pollution. The MP study is still in its infancy stage since it continues to be hampered by a lack of defined protocols and methodologies for investigating MPs in the laboratory. The use of MPs in laboratory research necessitates precise particle characterization to link the impacts of microplastics to their characteristics. To understand microplastic transit, deposition, and toxic effects, it is vital to distinguish between MP particles and those that are not. This thesis has primarily focused on the application of a new technology for analyzing MPs, based on Near-Infrared Spectroscopy (NIRs). As revealed by the bibliometric analysis of characterizing MPs by Fourier-Transformation Infrared Spectroscopy (FTIR) and Near-Infrared Spectroscopy, NIRs have only lately been applied, notably in the form of the miniaturized spectrometer (NIRs). Although NIR spectroscopy has been used as a standard tool for online quality assurance in food manufacturing and pharmaceuticals for decades, its ability to analyse microplastics in various environmental matrices has only recently been recognized. The workflow of this thesis begins with the use of handheld MicroNIR to analyse urban plastic garbage and construct an in-house NIR spectrum library, showcasing the usage of portable technology in the recycling sector. Because most libraries are constructed with virgin polymers, spectral shifts caused by MPs degradation are frequently missed. As a result, a new, more durable library searching algorithm capable of dealing with the difficulty of comparing degraded MPs to pristine polymer references was necessary. The second section discussed the significance of using reference materials in MP research and compares three techniques for producing MPs for research laboratories. This work will make it easier to comprehend the morphologies of MPs produced from the same parent particle using diverse techniques in a short period, allowing MP research to accelerate. The third section is based on the proof-of-concept study to analyse mixtures of microplastics through a handheld Near-Infrared Spectrometer. Given that, this study has proven the possibility of a portable tiny near-infrared spectrometer (MicroNIR) paired with chemometric methodologies for the measurement of secondary MPs mixes created at a laboratory scale for the first time. Extraction and purification are followed by identification and quantification in the MP analysis. The extraction of MPs from any environmental matrix is the most important phase since it is controlled by the matrix type and microplastic's size, shape, and density. As a result, the extraction technique should be tailored to the type of matrix under consideration. Following this idea, a comprehensive description of microplastic extraction processes distinguished by environmental matrix is offered at the end of this thesis in the form of a review. With concluding remarks, the final chapter gives a glimpse into the study's future prospects.

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PINNA, ANDREA. « Nanoporous Metals : Fabrication and Structure-Properties Relationship ». Doctoral thesis, Università degli Studi di Cagliari, 2022. http://hdl.handle.net/11584/332684.

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Nanoporous metals represent a unique class of materials with promising properties for a wide set of applications in advanced technology. Their combined self-supported monolithic form, high surface area, and high electrical conductivity are only the most obvious peculiarities of this kind of material. Since the beginning of an intensive work in 2001, nanoporous metals have shown high potential and tunable properties. However, the effective use in real applications is hampered by some challenging issues, such as the difficult fabrication of low-cost metals in a nanoporous form, the mechanical fragility and the low stability in certain working environments, i.e. electrolytes or high temperatures, and by the lack of a full understanding of the origin of some peculiar properties. The work presented in this thesis has been done with the purpose to address these issues. The fabrication of nanoporous metals and related composites has been studied to enlarge the possible properties of the common nanoporous gold and copper, and at the same time to find new strategies for the fabrication of nanoporous aluminum, a promising material for its low-cost, low-density, high electrical conductivity and corrosion resistance. Moreover, nanoporous gold thermal stability and behavior toward the degradation of organic dyes were further explored.

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CLEMATIS, DAVIDE. « Among old materials and different approaches to enhance stability and electrochemical activity of Solid Oxide Cells ». Doctoral thesis, Università degli studi di Genova, 2019. http://hdl.handle.net/11567/943333.

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Perovskite materials are widely studied as cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFC) for their relevant properties regarding electrocatalytic activity or stability. Nevertheless, a material that combines both it is not yet available. Among them, La1-XSrxMnO3 (LSM), La1-xSrxCo1-yFeyO3 (LSCF), Ba1-xSrxCo1-yFeyO3 (BSCF), La1-xSrxFeO3 (LSF), La1-xBaxCoO3 (LBC), were deeply investigated but their properties are not completely exploited or optimized. In this PhD project all the reported electrode materials are investigated using different approaches. The study starts from LSM – based electrodes, which show a change in kinetic mechanism under particular operating conditions. These results open new horizons about the employment of this material, up today considered not suitable for IT-SOFC temperature range. A first application, with promising results, is proposed here with a LSM infiltration in LSCF and BSCF scaffold. The presence of infiltrated-phase enhance stability and electrochemical activity of electrodes. Promising results are obtained also by mixing BSCF and LSCF powders. Three different BSCF:LSCF ratio are considered to produce three different cathodes. All the new compositions show an improvement of activity for oxygen reduction reaction, with very competitive values of polarization resistance. Moreover, one of these new electrodes has also a lowering of degradation rate compared with reference materials In the last year of this project, other two materials are combined and their interactions investigate. LSF, providing a high stability, is coupled with LBC, which has a really high surface electrocatalytic activity. The two materials are tested in different thin film systems. When they are mixed before the sintering stage react forming a new perovskite phase (Ba0.099Sr0.297La0.594Fe0.8Co0.2O3), with a higher activity. The reaction is avoided producing a bilayer system, and the presence of LBC top layer over a LSF dense thin film drastically reduces polarization resistance, highlighting promising results.

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Corvino, Raffaele. « Advanced polymeric composites for self-healing structural materials ». Doctoral thesis, Universita degli studi di Salerno, 2012. http://hdl.handle.net/10556/603.

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2010 - 2011
This research work rises from collaborative activities between Alenia Aeronautica (Pomigliano D’Arco, Napoli) and the Industrial Engineering Department of University of Salerno. One of the biggest challenge facing materials scientists is the idea to put in action self-healing composites in aeronautical applications. Polymeric composite materials, recently introduced in aeronautics, are subject to weakening due to mechanical, chemical, thermal, stress. This could lead to the formation of microcracks deep within the structure where detection and external intervention are difficult or impossible. The presence of the microcracks in the polymer matrix can affect both the fiber and matrix dominated properties of a composite. In the case of a transport vehicle, the propagation of microcracks may compromise the structural integrity of the polymeric components, and so threatening passengers’ safety. In this work, we have developed a multifunctional autonomically healing composite with a selfhealing functionality active at the severe operational conditions of aircrafts (temperature range: -50 °C/80 °C). The self-repair function in this new self-healing system, inspired by the design of White et al., is based on the metathesis polymerization of ENB (or ENB/DCPD blend) activated by Hoveyda-Grubbs’1st generation catalyst. The self-healing epoxy mixture, containing Hoveyda-Grubbs’1st generation catalyst, allows a cure temperature up to 180 °C without becoming deactivated. A quantitative assessment of self-healing functionality showed very high values of selfhealing efficiency. Before reaching these amazing results several systems were investigated that differ for the nature and the composition of the epoxy matrix, catalysts and active monomers used:these systems have been gradually improved to suit performance requirements for a structural advanced material to be applied to aeronautical vehicles. [edited by the author]
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Musella, Simona. « Design and synthesis of new polycyclic compounds with potential anticancer activity ». Doctoral thesis, Universita degli studi di Salerno, 2011. http://hdl.handle.net/10556/140.

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p53 is best known as a tumor suppressor that transcriptionally regulates, in response to cellular stresses such as DNA damage or oncogene activation, the expression of various target genes that mediate cell-cycle arrest, DNA repair, senescence or apoptosis—all of these cellular responses are designed to prevent damaged cells from proliferating and passing mutations on to the next generation. In 50% of human cancers, p53 is defective due usually to somatic mutations or deletions primarily in its DNA-binding domain and, to a lesser extent, to posttranslational modifications such as phosphorylation, acetylation and methylation that affect p53 function and stability. Altered p53 fails to regulate growth arrest and cell death upon DNA damage, directly contributing to tumor development, malignant progression, poor prognosis and resistance to treatment. Conversely, restoring endogenous p53 activity can halt the growth of cancerous tumors in vivo by inducing apoptosis, senescence, and innate inflammatory responses. cycle arrest, apoptosis, or senescence. While p53 plays a protective role in normal somatic tissues by limiting the propagation of damaged cells, its powerful growth suppressive and proapoptotic activity could be turned into a powerful weapon against cancer cells that have retained the functionality of the p53 pathway. Searching for small-molecules that activate the transcriptional activity of p53 would be expected to lead to the discovery of both DNA-damaging agents and compounds that are specific for the p53 pathway, including agents that interact directly with p53 or that inhibit MDM2 a negative regulator of p53 activity and stability. MDM2 is overexpressed in many human tumors and effectively impairs the function of the p53 pathway. Therefore, restoration of p53 function by antagonizing MDM2 has been proposed as a novel approach for treating cancer, and studies using macromolecular tools have shown its validity in vitro. II According to these findings, and as part of a wide medicinal chemistry program aimed at identifying small-molecules endowed with antitumor activity, different series of natural compound-inspired derivatives were designed as potential p53 modulators. Specifically, my PhD thesis work has been centered on two projects: the first was based on the design and synthesis of carbazole derivatives as DNA- damaging agents; while the second was based on the valuation of natural product analogues designed as both cellular cycle modulators and p53-MDM2 interaction inhibitors. The final aim of this study was to identify of suitable leads which allow us to deep on the molecular complexity of p53 network, improving the antitumor therapeutic arsenal The role of natural products as a source for remedies has been recognized since ancient times. Despite major scientific and technological progress in combinatorial chemistry, drugs derived from natural product still make an enormous contribution to drug discovery today. The development of novel agents from natural sources presents obstacles that are not usually met when one deals with synthetic compounds. For instance, there may be difficulties in accessing the source of the samples, obtaining appropriate amounts of the sample, identification and isolation of the active compound in the sample, and problems in synthesizing the necessary amounts of the compound of interest. An analysis of the number of chemotherapeutic agents and their sources indicates that over 60% of approved drugs are derived from natural compounds. During my PhD thesis work three different structural motives present in natural products have been considered to be suitable scaffold in the design of new antitumoral agents: carbazoles, acridines and spirooxindole derivatives. Carbazoles either in a pure substituted or in an annellated substituted form, represent an important and heterogeneous class of anticancer agents, which has grown considerably over the last two decades. Recently, Wong et al. have described a particular activity of a series of acridine derivatives characterized III by a polycyclic planar system and by a side chain ending with a tertiary amine, act stabilized p53 protein by blocking its ubiquitination, without phosphorylation of ser15 or ser20 on p53. Furthermore, these derivatives induced p53-dependent cell death, activating p53 transcriptional activity Based on the structural cytotoxic requirements for these class of products my first PhD project was centered on synthesis of two series of compounds in which a carbazole eskeleton were linked by an alkyl chain to an amine (series 1) or substituted amide (series 2) groups. In the other hand, small molecule natural products containing spirooxindole derivatives have demonstrated to be invaluable tools in the discovery and characterization of critical events for the progression and the regulation of the cell cycle. Based on the spirotryprostatin-A structure, during my PhD project II I designed, synthesized, and evaluated different series of compounds belonging to the diketopiperazine structural class as potential cell cycle modulators and cytotoxic agents. Starting from the spirooxindolthiazolidine scaffold, amide coupling with Pro derivatives and intramolecular cyclization reactions are suitable synthetic methods to generate chemically diverse diketopiperazine system, such as hexahydropyrrolo[1,2-a][1,3]thiazolo[3,2-d]pyrazine-5,10-dione (structure I), hexahydropyrrolo[1,2-a] [1,3]thiazolo[3,4-d]pyrazine-5,10-dione (structure II) and, spiroindol-2-one[3,30]hexahydro-5,10H-pyrrolo[1,2-a][1,3]thiazolo[3,4-d]pyrazine-5,10-dione (structure III). Some of these compounds, especially those who belong to the series I and II, showed interesting cytotoxic activity. In the last part of my project, I have designed and synthesized two libraries of compounds based on the spirooxindol-thyazolidine moiety, analogues of spirooxoindol-pyrrolidine template as p53-MDM2 inhibitors. Compounds (3R,7aR)-6-(4-chlorobenzyl)-1H-spiro[imidazo[1,5-c]thiazole-3,3‘-indoline]-2‘,5,7(6H,7aH)-trione (42c) and (3R,7aR)-50-methyl-6-(3,4,5-trimethoxybenzyl)-1H-spiro[imidazo-[1,5-c]thiazole-3,3‘-indoline]- IV 2‘,5,7(6H,7aH)-trione (43d) are the most potent compounds of this series, inhibiting cell growth of different human tumor cells at submicromolar and micromolar concentrations, respectively. Compound 42c induces apoptotic cell death in human melanoma cell line M14 at 24 h, while in the same condition, treatment with 43d shows a clear arrest at G2/M phase inducing delay of cell cycle progression. Possibly, these activities may be due to inhibition of p53-MDM2 interaction and subsequent p53 release and activation. [edited by author]
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Calabrese, Elisa. « Multi-functional self-healing materials for structural application ». Doctoral thesis, Universita degli studi di Salerno, 2019. http://elea.unisa.it:8080/xmlui/handle/10556/4299.

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2017 - 2018
Main objective of this PhD thesis is the development of a new generation of self-healing multifunctional composites able to overcome some of the current limitations of aeronautical materials, such as: absence of auto-repair mechanisms integrated in the composite structure, reduced electrical conductivity and poor impact damage resistance. Structural aeronautical systems experience a broad spectrum of environmental and operational loads and atmospheric hazards (hail, lightning, storms etc.). Severe and/or prolonged load exposures may trigger the damage accumulation process even in recently deployed structures. Modern airframe design is exploiting new exciting developments in materials and structures to construct ever more efficient air vehicle able to enable ‘smart’ maintenance including self-repair capabilities. Relevant challenges for many of the already developed self-repairing systems are to enhance the structural stability, and the resistance to the atmospheric hazards through specific functions integrated in the material. The traditional approach to the development of aeronautic materials is to address the load-carrying and other functional requirements separately, resulting in a suboptimal load-bearing material with the penalty of added weight. The research activity of this PhD thesis is aimed to develop self-healing, load-bearing materials with all functionalities integrated in a single material able to meet many important requirements of this kind of materials. The main concept underpinning this PhD project is the use of the nanotechnology strategy for the production of new, high mechanical performance multifunctional materials. Based on recent developments in the field of nanotechnologies and successful strategies identified in recently papers and patents, the main objectives of this thesis have been achieved. The performed research activities allowed the implementation of a new generation of self-healing composites, which also considers relevant aspects related to the need of developing environmentally-friendly materials for transports. In this project, many different approaches have been considered for each functionality in order to reduce the risk of failure. Alternative concepts with respect to designs already proposed in literature have been explored. Multifunctional resins prepared using chemicals not commercially available yet have been developed and characterized. ... [edited by Author]
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SANTIBANEZ-MENDIETA, ALMA BEATRIZ. « Sr0.02La0.98Nb1-xTaxO4 as a novel, chemically stable proton conducting electrolyte ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/202319.

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Sr0.02La0.98Nb0.6Ta0.4O4 proton conductor oxide was prepared by auto-combustion and coprecipitation methods from an aqueous solution using citrates and oxalates as complexing agents. After calcinations at 1100 °C the two methods lead to powders with sub-micrometric average particle size, 0.5 μm and 0.7 μm respectively. Upon sintering at 1600 °C, pellets with an average grain size of 11 μm for the auto-combustion method and of 7 μm for the co-precipitation method were obtained. The electrical conductivity measured on sintered pellets at 800 °C in wet argon atmosphere was 1.9×10-4 Scm-1 for the material obtained by co-precipitation method, 1.8×10-4 Scm-1 for the one derived from auto-combustion method and 7.4×10-4 Scm-5 for the one produced by solid state reaction. The improvement in conductivity of the wet chemistry methods with respect to the solid state reaction was ascribed to the higher control of the cationconcentration with the synthetic conditions. Sr0.02La0.98Nb1-xTaxO4 (SLNT, with x= 0.1, 0.2, 0.4) proton conducting oxides were synthesized by solid state reaction for application as electrolyte in solid oxide fuel cells operating below 600 °C. Dense pellets were obtained after sintering at 1600 °C for 5 h achieving a larger average grain size with increasing the tantalum content. Dilatometric measurements were used to obtain the SLNT expansion coefficient as a function of tantalum content (x), and it was found that the phase transition temperature increased with increasing the tantalum content, being T = 561, 634 and 802 °C for x= 0.1, 0.2 and 0.4, respectively. The electrical conductivity of SLNT was measured by electrochemical impedance spectroscopy as a function of temperature and tantalum concentration under wet (pH2O~ 0.03 atm) Ar atmosphere. At each temperature, the conductivity decreased with increasing the tantalum content, being at 600 °C 2.68×10-4, 3.14×10-5, and 5.41×10-6 Scm-1 for the x= 0.1, 0.2, and 0.4 compositions, respectively. SLNT with x= 0.2 shows a good compromise between proton conductivity avoiding the detrimental phase transition for application as electrolyte below 600 °C.

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Vertuccio, Luigi. « Nanofilled epoxy adhesive for structural aereonautic materials ». Doctoral thesis, Universita degli studi di Salerno, 2017. http://hdl.handle.net/10556/2588.

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2015 - 2016
The focus of this study is to design new nano-modified epoxy adhesives using carbon nanofillers such as carbon nanotubes, carbon nanofibers and exfoliated graphite. Kinetic analysis, transport properties, dynamic mechanical properties and electrical properties have shown to be a powerful means for understanding molecular structure and phase composition of the formulated nanocomposites. Kinetic analysis, performed by using an advanced iso-conversional method and the Kamal’s model-diffusion controlled respectively, has shown which, in epoxy resin, based on the tetrafunctional epoxy precursor N,N′-tetraglycidyl methylene dianiline-(TGMDA) hardened with 4,4-diaminodiphenyl sulfone (DDS), the introduction of the diluent decreases particularly the activation energy of secondary amine-epoxy reaction. The inclusion in the resin of one-dimensional fillers does not lead to big differences in the curing kinetics behaviour with respect to the raw epoxy. An increase in the activation energy is found in the case of highly exfoliated graphite. It is likely due to a reduction of free molecular segments of the epoxy network entrapped inside self-assembly structures. Transport properties have shown that, using a non-stoichiometric amount of hardener, the chemical structure of epoxy mixture exhibits unique properties concerning the water sorption for which the Equilibrium Concentration of Water is reduced up to a maximum of 30%. Dynamic mechanical analysis have shown that the nanoparticles are responsible of a more mobile phase, in the structure of the resin, determining an additional glass transition at lower temperature with respect to the main glass transition temperature. The fraction of the more mobile phase is strictly related to the amount and nature of the nanofiller and to the amount of the hardener, in fact, using a non-stoichiometric amount of hardener, also the electrical properties are improved further. The adhesive formulations based on epoxy/nanostructured carbon forms are used to obtain both adhesive and adherents to order to evaluate the adhesion properties with different joint configurations (tensile butt joint and single lap joint). The inclusion of carbon nanofillers inside the epoxy adhesive caused a significant improvement in the bond strength of the joints, changing the failure mode of joints in single lap joint shear tests. Finally, the conductive adhesive carbon nanotubes based, have been modified, by introduction of an elastomer, to order to obtain high performance in the configuration lap shear strength (LSS) with adherents in carbon fiber reinforced plastics (CFRP) used in aeronautic field. A correct combination of elastomer and carbon nanotubes, has allowed obtaining a conductive adhesive with high performance. [edited by author]
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Bugatti, Valeria. « Dispersion of inorganic fillers in polymeric matrices for food packaging applications ». Doctoral thesis, Universita degli studi di Salerno, 2012. http://hdl.handle.net/10556/274.

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2010 - 2011
The objective of this PhD project regards the formulation, preparation and characterization of polymeric materials in which lamellar inorganic solids containing potentially active molecules are dispersed. In particular the present work was aimed at the preparation and characterization of "Active Food Packaging Materials" using inorganic fillers modified with active molecules (antimicrobials, antioxidants) dispersed in polymeric matrices for the realization of: 1) Materials with improved barrier properties to gases and vapors 2) Systems for controlled release of active molecules, act to protect and extend the shelf life of food products. Two techniques of dispersion of active inorganic fillers in polymer matrices have been used, generating: 1) polymeric nanocomposites 2) coatings of polymeric surfaces. A screening of different polymers, from biodegradable and thermoplastic to natural, was done to compare the effect of the fillers and of the dispersion technique on the properties mentioned above.[edited by author]
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Brigolin, Daniele <1978&gt. « Development of integrated numerical models for the sustainable management of marine aquaculture ». Doctoral thesis, Università Ca' Foscari Venezia, 2007. http://hdl.handle.net/10579/535.

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FIORI, ANGELAMARIA. « Sintesi e caratterizzazione delle proprietà di emissione di campo di materiali nanostrutturati a base carbonio ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/778.

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Due to their novel properties, nanostructured carbon materials are concentrating more and more efforts within the scientific community. The latest members of this ever increasing family, carbon nanotubes, have been indicated as the most interesting and promising material both from a purely scientific and technological point of view. Field emission based devices are considered their closest to market technological application. Synthesis and characterization of such structures represents, therefore, key tasks in material science research. Within such framework, the three-year work reported in this thesis face the challenge in optimizing the deposition of Single Wall Carbon Nanotubes (SWNTs), synthesizing a new hybrid nanostructured material consisting of diamond and SWNTs and investigating their field emission properties. As for the synthesis step, a modified Hot Filament Chemical Vapor Deposition set-up was used. Carbon nanopowders were used as carbon feedstock, plain and lithographically patterned Si as substrates; different morphologies of SWNT bundles were obtained. By slightly varying the synthesis conditions and getting longer deposition times a new hybrid material constituted by a diamond outer phase and a SWNT inner phase was obtained. For both the plain (SWNTs) and hybrid (SWNTs-diamond) selected area growth onto predefinite areas was achieved. Field emission investigation was carried out by using a home-made set-up which enabled the I-V characterization of the samples. Being interested in the quantitative comparison of morphologically different samples, a simple, new and reliable measurement methodology has been set up. Procedures for the evaluation of interelectrode distance and emitting area are presented: as for the former, a capacimetric approach is described; as for the emitting area evaluation, an approximated analytical formula is proposed. A quantitative comparison among three samples showing different features is carried out: extraction fiel is found out to increase as the density of the SWNT bundles increase. The results are explained in term of mutual field screening. A preliminary study on the diamond/nanotubes hybrid material revealed favourable field emission properties. The novelty of such structures lead me to go deeper in the investigation: a study of the emission pattern and of the energy spectrum in systematically different experimental conditions was carried out. A unusual, never-seen spectrum consisting of many sharp peaks located within 500 eV from the Fermi level was recorded. We explained this behavior by invoking the highly resistive nature of diamond. We consider our results as referring to the truly intrinsic properties of the outer diamond. As a result of the field emission investigation two field emission devices are proposed: a triode and a X-ray tube.

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Bonizzoni, L. M. « L'analisi chimica nello studio delle ceramiche archeologiche ». Doctoral thesis, Università degli Studi di Milano, 2006. http://hdl.handle.net/2434/30252.

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As regards archaeological pottery, information about provenance and production technology (for instance, firing temperature) can be deduced from chemical and mineralogical composition.The first part of the work has been devoted to the possibility of applying different techniques both of elemental and mineralogical analysis to the classification of the sherds: i) a method based on the mutual integration of ICP-AES and FTIR analyses, introducing the novelty of a semiquantitative analysis of mineralogical phases obtained by PLS regression; mineralogical and elemental data are then treated by chemometrical tools (PCA and cluster analyses); ii) the possibility of obtaining quantitative non-invasive elemental analysis directly in the museum exploiting ED-XRF analysis; iii) TXRF analysis allowing to avoid chemical digestion of the sample. The second part of the work deals with the classification of five groups of ceramic samples, i.e.: impasto Etruscan pottery from La Castellina, Etruscan pottery and grey bucchero from Tarquinia, Etruscan pottery from Cerveteri kept in the Archaeological Museum in Milan, medieval and Roman pottery from Tarquinia, Euboean pottery from Eretria.

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CASTELLI, FILIPPO. « Foul-control paints behavior near anodes of Impressed Current Cathodic Protection systems ». Doctoral thesis, Università degli studi di Genova, 2023. https://hdl.handle.net/11567/1104637.

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It is known by foul control paint and Impressed Current Cathodic Protection system producers that paints can fail in proximity of the anodes. This failure is well known in industrial field, but does not represent a structural problem. As a matter of fact, paint recovery is performed within routinary docking operations. Within this framework, it is interesting to evaluate the behavior of new generation biocide-free foul control paints under a chemical stress resembling that near ICCP anodes, where seawater turns acidic and chlorinated. Data in this area have not been already studied nor published. The values of free chlorine and pH produced at anodes, to which paints are exposed, were obtained experimentally. Two biocide free paints, a foul release (FR) and an amphiphilic self-polishing (SP), were chosen for testing on these conditions. Paints were exposed to a 3x3 matrix of 'pH/free-Cl' different conditions. After 3 months of immersion in the selected environments, a physical-chemical characterization was performed through: visual inspection, detachment area analysis, thickness variation, contact angle variation, profilometry and IR. Laboratory and field tests were finally performed to evaluate the foul-control properties after treatments. Results showed that the degradation is mainly induced by free chlorine oxidation, and acidity strengthens the chemical attack. Both paints in the harshest condition were disbonded. Foul release paint seems generally more stable but detaches easily from the primer, while the amphiphilic SP is apparently less prone to detachment from the primer, but exhibits modification of its physical properties. Foul-control properties did not show a substantial drop after the conditioning treatment, but the tests reported detachment of both paints in conditions in which it was not previously observed.

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Valarezo, Valdez Benito Eduardo. « Innovative processes for the production of new nanocomposite materials by electrospinning technique ». Doctoral thesis, Universita degli studi di Salerno, 2013. http://hdl.handle.net/10556/1474.

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2011 - 2012
The technical parameters for electrospinning solutions of biodegradable polymers poly(ε-caprolactone), poly(lactic acid) and their composites with active molecules were defined and set up. A trial-and-error approach has been employed by varying solution properties and processing parameters to obtain uniform defect-free fibers. Amoxicillin drug was intercalated in layered double hydroxide nanoparticles by coprecipitation and then the modified nanohybrid was successfully encapsulated at different concentrations into poly(ε-caprolactone) matrix by the electrospinning technique. Non-woven fibrous mats were fabricated and characterized in terms of morphology, in vitro release and antibacterial properties. Blends of poly(lactic acid) and poly(ε-caprolactone), loaded with different amounts of amoxicillin were electrospun to investigate the release behaviour and obtain a controlled and tuneable release. Morphology and thermal behaviour were found dependent on the component ratio as well as on the incorporated drug amount. [edited by author]
XI n.s.

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48

Zheng, Jian. « Model electrocatalysts for fuel cells : a surface science based study ». Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3424615.

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The present thesis focuses on studying structure/morphology/activity relationships in bimetallic Pt-Sn nanostructured electrodes for proton exchange membrane (PEM) fuel cells by adopting a rigorous surface science approach where: i) Model electrocatalysts are prepared in ultra-high-vacuum (UHV) conditions as ultrathin (UT) films (PtSnx/Pt(110) and SnOx/Pt(110)) to ensure a very reproducible control down to the atomic level; ii) Composition, morphology and structure of the UT nanostructured films are studied in situ by adopting state-of-the-art characterization tools; iii) Quantum mechanical calculations are carried out adopting the density functional theory (DFT) in order to determine the atomic structure of the UT films. A systematic search for possible Sn alloy or oxides on Pt(110) surface phases was carried out. Three surface alloys (including one already reported surface alloy) and two surface oxides on Pt(110) surface were identified. The two novel surface alloys: p(3×1)PtSn/Pt(110) and p(6×1) PtSn/Pt(110) can be prepared by means of UHV Sn deposition on Pt(110) at different thickness and by a subsequent annealing at proper temperature. Besides, two SnOx oxides surfaces, namely the c(2×4)SnOx/Pt(110) and the c(4×2) SnOx/Pt(110), were prepared by oxidizing the surface alloys. With optimization of the preparation conditions, a phase diagram for the surface alloys and surface oxides on Pt(110) was outlined. The two novel surface alloys were characterized by low energy electron diffraction (LEED), scanning tunnelling microscopy (STM) and synchrotron radiation photoemission spectroscopy (SRPES). STM images of the two surface alloys are characterized by a highly corrugated row structure whereas photoemission data indicate a complex intermixing between Pt and Sn which leads to the formation of extended near-surface alloys. Some models for the two surfaces were proposed on the basis of the experimental evidences. These models were then compared with DFT calculations and the simulated STM images of the models were used as final assessment of their validity. The reactivity of the surface alloys with CO was investigated both experimentally by thermal programmed desorption (TPD) and theoretically by DFT calculations. The results reveal a scarce reactivity towards CO on the two surfaces due the lower adsorption energy with respect to pure Pt(110) surface, indicating their use as highly CO tolerant catalysts. Based on the DFT results, the surfaces can have also an improved performance in CO oxidation reaction (COOR) on the basis of the calculated d-band centroid value. The two surface oxides (c(2×4)SnOx/Pt(110) and c(2×4)SnOx/Pt(110) ) were investigated by LEED, STM and SRPES. Some models for the two surfaces were proposed based on the experimental results, and investigated by DFT calculations. The good agreement between the simulated STM images with the experimental data suggests a good reliability of the proposed structures. The reactivity towards CO for the two oxidised phases was also investigated. The c(4×2) structure, constituted by a slightly oxidised Sn overlayer, demonstrated to be scarcely reactive, whereas the more oxidized c(2×4) phase proved to be able to efficiently oxidize CO. These results were also confirmed by DFT. The decomposition of methanol on c(2×4) surface was also investigated by TPD and SRPES, indicating that the methanol can be oxidised efficiently into CO2 and H2O. However the body of our experimental data points to a quite complex oxidation mechanism whose selectivity changes dynamically according to the experimental conditions. The fully oxidised c(2×4) can efficiently oxidise methanol to CO2 at low temperature, but this reaction path is progressively suppressed as soon as the phase is reduced. In this regime the methanol is oxidized to CO2 at higher temperature and less efficiently, the microscopic mechanism of the reaction implies the supply of oxygen by c(2×4) islands on reduced Pt or PtSn areas by spillover, where the actual reaction takes place. When the spillover is not anymore possible, because the methanol decomposition has removed most oxygen, methanol is simply oxidatively dehydrogenated to CO and H2, similarly to what happens on the clean Pt(110) surface but at a slightly lower temperature.
La presente tesi si concentra sullo studio della relazione struttura / morfologia / reattività in elettrodi bimetallici nanostrutturati Pt - Sn per celle a combustibile a membrana a scambio protonico (PEM), adottando un rigoroso approccio di scienza delle superfici sviluppato come segue: i) sistemi modello di elettrocatalizzatori sono stati preparati in condizioni di ultra - alto vuoto (UHV) depositando via epitassia da fasci molecolari (MBE) strati ultrasottili (UT) di PtSnx e SnOx su superfici di Pt monocristallino orientate (110), al fine di garantire un controllo fine e riproducibile su scala atomica; ii ) composizione, morfologia e struttura dei film nanostrutturati UT sono stati studiati in situ mediante l'adozione di strumenti di caratterizzazione in linea con le più avanzate tecniche offerte dallo stato dell’arte; iii ) calcoli quanto-meccanici basati sulla teoria del funzionale densità (DFT) sono quindi stati effettuati per determinare la struttura atomica dei film UT, in modo da razionalizzare e supportare i risultati sperimentali ottenuti al punto precedente. Una ricerca sistematica è stata effettuata allo scopo di identificare nuove possibili fasi di superficie di Sn o ossidi di Sn supportate su Pt (110). In questo modo, tre leghe di superficie (di cui una risulta già nota in letteratura) e due ossidi di superficie su Pt (110) sono stati identificati. Le due innovative leghe da film UT, la p(3 × 1) PtSn / Pt (110) e la p(6 × 1) PtSn / Pt (110) possono essere sintetizzate mediante deposizione di Sn su Pt (110), preparando spessori diversi e sottoponendo le superfici così ottenute a trattamenti termici effettuati a diverse temperature. Conseguentemente, l’ossidazione ad alta temperatura delle leghe superficiali ha permesso l’ottenimento di due nuove fasi ossidate di superficie, la (c(2 × 4) SnOx / Pt (110) e la c(4 × 2) SnOx / Pt (110). Infine, data l’elevata flessibilità delle tecniche di preparazione e caratterizzazione offerte dalla scienza delle superfici, è stato possibile delineare con grande accuratezza un diagramma di fase sia per le leghe che per gli ossidi di superficie sopra descritti. Le due nuove leghe superficiali sono state caratterizzate mediante diffrazione di elettroni a bassa energia cinetica (LEED), microscopia a scansione ad effetto tunnel (STM) e spettroscopia di fotoemissione da radiazione di sincrotrone (SRPES). Le immagini STM delle due leghe superficiali sono caratterizzate da una struttura a righe altamente corrugata; i dati di fotoemissione indicano inoltre un complesso intermixing tra Pt e Sn che porta alla formazione di leghe localizzate in prossimità della superficie. Alcuni modelli per le due superfici così ottenute sono state proposte sulla base delle evidenze sperimentali. Tali modelli sono stati poi confrontati con calcoli DFT; in particolare, sono state generate simulazioni di immagini STM che sono state quindi confrontate con i dati sperimentali ed usate come valutazione finale della validità dei modelli proposti. La reattività delle leghe di superficie rispetto al CO è stata studiata sia sperimentalmente, mediante desorbimento termico programmato (TPD), sia ricorrendo a calcoli DFT. I risultati rivelano una scarsa reattività delle due superfici nei confronti del CO a causa dell’energia di adsorbimento inferiore rispetto alla stessa superficie di Pt (110) presa come riferimento; tale fenomenologia indica pertanto il promettente impiego di tali sistemi come catalizzatori caratterizzati da elevata tolleranza al CO. Come già descritto per le leghe di superficie, i due ossidi superficiali (c(2 × 4) SnOx / Pt (110 ) e c(4 × 2) SnOx / Pt (110) ), sono stati studiati mediante LEED, STM e SRPES. Alcuni modelli per le due superfici sono stati proposti sulla base dei risultati sperimentali, la cui validità è stata supportata da calcoli DFT. Il buon accordo tra le immagini STM simulate e i dati sperimentali suggeriscono una buona affidabilità delle strutture proposte. La reattività verso il CO per le due fasi ossidate è stata inoltre indagata mediante TPD supportata da calcoli quantomeccanici. La struttura c(4 × 2), costituita da uno strato UT di SnOx sub-stechiometrico, ha dimostrato di essere poco reattiva, mentre la fase più ossidata c(2 × 4) ha dimostrato di essere in grado di ossidare efficacemente il CO. Lo studio della decomposizione del metanolo sulla fase c(2 × 4), effettuato mediante TPD e SRPES, indica come il metanolo possa essere ossidato in modo efficiente a CO2 e H2O. Tuttavia, i dati sperimentali indicano un meccanismo di ossidazione piuttosto complesso, la cui selettività cambia dinamicamente in base alle condizioni sperimentali. Ad ogni modo, la fase completamente ossidata c(2 × 4) può facilmente ossidare il metanolo a CO2 già a bassa temperatura, tuttavia tale reattività viene progressivamente soppressa non appena inizia la riduzione della fase con la perdita di ossigeno reticolare. In questo regime l’ossidazione del metanolo a CO2 richiede temperature più elevate; in particolare, il meccanismo microscopico della reazione implica la fornitura di ossigeno da parte della fase c(2 × 4) ad isole ridotte di Pt o PtSn, siti nei quali avviene effettivamente la reazione di ossidazione. Con il procedere della decomposizione del metanolo, il progressivo consumo di ossigeno porta ad una drastica soppressione della diffusione di superficie di quest’ultimo. In questo modo, il metanolo viene semplicemente deidrogenato a CO e H2 analogamente a quanto accade sulla superficie pulita di Pt (110), sebbene a temperature inferiori.

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URSO, DANIELE. « Sistemi a base di chitosano per applicazioni farmacologiche ». Doctoral thesis, Università degli studi di Genova, 2019. http://hdl.handle.net/11567/940929.

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This PhD work is about the implementation of innovative chitosan-based Drug Delivery Systems (DDSs) for the cure of periodontal disease. Current treatment of this pathology consists of localized administrations of antibiotic and anti-inflammatory drugs, but repeated therapeutic sessions have negative consequences on the patient’s quality of life. In the present work novel potential drug delivery systems have been investigated with the aim of administering drugs and simultaneously promoting the regeneration of damaged tissues. To this purpose chitosan has been chosen because of its unique properties including biocompatibility, biodegradability, mucoadhesivity, antimicrobial and wound-healing capabilities. Three types of chitosan-based systems have been studied: microbeads with internal sponge-like architecture, obtained by drop-to-drop coagulation of an acetic chitosan solution in a EtOH/ NH3/H2O bath, films obtained by drop-casting, and membranes prepared by electrospinning from an aqueous mixture of chitosan and poly(ethylene oxide). The uptake and release properties of these systems have been tested with the antibiotic drug Doxycycline hydrochloride (DC) and the anti-inflammatory drug Triamcinolone acetonide (TC). Freundlich and pseudo second-order kinetic equations have been applied to describe the processes at varying the drug concentrations. The most relevant results obtained from this PhD work show delayed drug release by microbeads and films, compatible with a controlled DDS behaviour, and highly increased DC uptake by electrospun membranes, likely due to their very porous structure.

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CIBECCHINI, GIULIA. « Point-of-care diagnostics for Single Nucleotide Polymorphisms genotyping : applications to food traceability, nutrigenetics and pharmacogenetics ». Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1041504.

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Single Nucleotide Polymorphisms (SNPs) are common genetic variations associated to specific phenotypes. SNPs have high relevance in different biomedical areas including both preventive/personalized medicine and non-clinical contexts, such food traceability. However, current techniques for SNP genotyping are expensive, require specialized laboratories and costly instrumentations, and are time consuming. In this framework, the development of rapid, point-of-care (POC) SNP diagnostic technologies would be of great interest, opening new possibilities for early, on-site screenings in multiple fields. In this PhD thesis, starting from state-of-art approaches, a rapid and portable diagnostic strategy based on Loop Mediated Isothermal Amplification (LAMP) has been developed for SNPs genotyping. In particular, the developed strategy was applied and validated, in a naked-eye colorimetric approach, for food varietal discrimination (i.e. durum wheat variety) in a model case of industrial relevance. Moreover, the POC technology was targeted to different salivary biomarkers, to address nutrigenetics and pharmacogenetics issues. Notably, the possibility to rapidly diagnose the genetic predisposition to lactose intolerance or the impairment of folic acid metabolism was proven. Furthermore, the developed POC-compatible protocols can work with portable, battery-powered devices, allowing for POC operation of such diagnostic tests.

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Thèses sur le sujet « CHIM/07 »

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